sql_utils

Sql utils are used to interact with databases.

execute_sql_queries_with_retry(db_connection_engine, queries, bulk_commit)

Executes a list of SQL queries with optional bulk commit and retry logic.

Connects to the database using the provided SQLAlchemy engine and executes each query in the given list. If bulk_commit is True, all queries are committed together after execution; otherwise, each query is committed individually. Retries up to 3 times with a 2-second wait between attempts in case of transient OperationalErrors.

Parameters:

Name	Type	Description	Default
db_connection_engine	Engine	The SQLAlchemy engine used to connect to the database.	required
queries	List[str]	A list of SQL queries to execute.	required
bulk_commit	bool	Whether to commit all queries in a single transaction.	required

Returns:

Name	Type	Description
int	int	The number of rows affected by the last executed query.

Raises:

Type	Description
OperationalError	If the connection or query execution fails after retries.

Example

from physical_operations_utils.sql_utils import execute_sql_queries_with_retry
from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

engine = get_db_connection(f"common_trading_data_{environment}").engine
queries = [
    "UPDATE my_table SET value = 1 WHERE id = 10",
    "DELETE FROM my_table WHERE value IS NULL"
]
rowcount = execute_sql_queries_with_retry(engine, queries, bulk_commit=True)
print(f"{rowcount} rows affected by the last query.")

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(3),
)
def execute_sql_queries_with_retry(
    db_connection_engine: Engine,
    queries: List[str],
    bulk_commit: bool,
) -> int:
    """
    Executes a list of SQL queries with optional bulk commit and retry logic.

    Connects to the database using the provided SQLAlchemy engine and executes each
    query in the given list. If `bulk_commit` is True, all queries are committed
    together after execution; otherwise, each query is committed individually.
    Retries up to 3 times with a 2-second wait between attempts in case of
    transient `OperationalError`s.

    Args:
        db_connection_engine (sqlalchemy.engine.Engine): The SQLAlchemy engine used to connect to the database.
        queries (List[str]): A list of SQL queries to execute.
        bulk_commit (bool): Whether to commit all queries in a single transaction.

    Returns:
        int: The number of rows affected by the last executed query.

    Raises:
        sqlalchemy.exc.OperationalError: If the connection or query execution fails after retries.

    Example:
        ```python
        from physical_operations_utils.sql_utils import execute_sql_queries_with_retry
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

        engine = get_db_connection(f"common_trading_data_{environment}").engine
        queries = [
            "UPDATE my_table SET value = 1 WHERE id = 10",
            "DELETE FROM my_table WHERE value IS NULL"
        ]
        rowcount = execute_sql_queries_with_retry(engine, queries, bulk_commit=True)
        print(f"{rowcount} rows affected by the last query.")
        ```
    """
    try:
        with db_connection_engine.connect() as conn:
            for query in queries:
                res = conn.execute(text(query))
                if not bulk_commit:
                    conn.commit()
            if bulk_commit:
                conn.commit()
            return res.rowcount
    except OperationalError as e:
        logging.error(f"OperationalError: {e}")
        logging.error(f"Original exception: {e.orig}")
        logging.error(f"Arguments: {e.orig.args}")
        raise e

get_existing_table_names(db_connection_engine)

Retrieves the names of all existing base tables from a database.

Connects to the database using the provided SQLAlchemy engine and queries the INFORMATION_SCHEMA.TABLES view to get the names of all base tables. Retries up to 3 times with a 2-second wait between attempts in case of transient OperationalErrors.

Parameters:

Name	Type	Description	Default
db_connection_engine	Engine	The SQLAlchemy engine used to connect to the database.	required

Returns:

Type	Description
List[str]	List[str]: A list of base table names present in the database.

Raises:

Type	Description
OperationalError	If the connection or query fails after retries.

Example

from physical_operations_utils.sql_utils import get_existing_table_names
from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

engine = get_db_connection(f"common_trading_data_{environment}").engine
table_names = get_existing_table_names(engine)
print(table_names)

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(3),
)
def get_existing_table_names(db_connection_engine: Engine) -> List[str]:
    """
    Retrieves the names of all existing base tables from a database.

    Connects to the database using the provided SQLAlchemy engine and queries the
    `INFORMATION_SCHEMA.TABLES` view to get the names of all base tables. Retries up
    to 3 times with a 2-second wait between attempts in case of transient `OperationalError`s.

    Args:
        db_connection_engine (sqlalchemy.engine.Engine): The SQLAlchemy engine used to connect to the database.

    Returns:
        List[str]: A list of base table names present in the database.

    Raises:
        sqlalchemy.exc.OperationalError: If the connection or query fails after retries.

    Example:
        ```python
        from physical_operations_utils.sql_utils import get_existing_table_names
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

        engine = get_db_connection(f"common_trading_data_{environment}").engine
        table_names = get_existing_table_names(engine)
        print(table_names)
        ```
    """
    try:
        with db_connection_engine.connect() as conn:
            tables_rs = conn.execute(
                text(
                    "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE';"
                )
            ).fetchall()
            return [table[0] for table in tables_rs]
    except OperationalError as e:
        logging.error(f"OperationalError: {e}")
        logging.error(f"Original exception: {e.orig}")
        logging.error(f"Arguments: {e.orig.args}")
        raise e

get_latest_task_execution_time_utc(platform_conn_engine, application_name, job_id)

Retrieves the last successful execution timestamp of a task from the platform task execution tracking table.

The function queries the core_last_successful_task_execution table for a specific application and job ID and returns the timestamp of the last successful execution in UTC. If no execution is found, it returns None. If more than one row is returned by the query, a ValueError is raised.

Parameters:

Name	Type	Description	Default
platform_conn_engine	Engine	SQLAlchemy engine to the platform database.	required
application_name	str	Name of the application that executed the task.	required
job_id	str	Identifier for the specific job/task.	required

Returns:

Type	Description
datetime | None	datetime.datetime | None: The UTC datetime of the last successful execution, or None if not found.

Raises:

Type	Description
ValueError	If more than one row is returned by the query.
Exception	If the database connection or query fails after retries.

Example

from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection
from physical_operations_utils.environment_utils import setup_environment
from physical_operations_utils.sql_utils import get_latest_task_execution_time_utc

environment = setup_environment()
engine = get_db_connection(f"physical_trading_platorm_django_{environment}")
last_run = get_latest_task_execution_time_utc(engine, "my_app", "my_task")

if last_run:
    print(f"Last successful execution: {last_run}")
else:
    print("No previous execution found.")

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(3),
    reraise=True,
)
def get_latest_task_execution_time_utc(
    platform_conn_engine: Engine, application_name: str, job_id: str
) -> datetime.datetime | None:
    """
    Retrieves the last successful execution timestamp of a task from the platform task execution tracking table.

    The function queries the `core_last_successful_task_execution` table for a specific application and job ID and
    returns the timestamp of the last successful execution in UTC. If no execution is found, it returns `None`.
    If more than one row is returned by the query, a `ValueError` is raised.

    Args:
        platform_conn_engine (Engine): SQLAlchemy engine to the platform database.
        application_name (str): Name of the application that executed the task.
        job_id (str): Identifier for the specific job/task.

    Returns:
        datetime.datetime | None: The UTC datetime of the last successful execution, or `None` if not found.

    Raises:
        ValueError: If more than one row is returned by the query.
        Exception: If the database connection or query fails after retries.

    Example:
        ```python
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection
        from physical_operations_utils.environment_utils import setup_environment
        from physical_operations_utils.sql_utils import get_latest_task_execution_time_utc

        environment = setup_environment()
        engine = get_db_connection(f"physical_trading_platorm_django_{environment}")
        last_run = get_latest_task_execution_time_utc(engine, "my_app", "my_task")

        if last_run:
            print(f"Last successful execution: {last_run}")
        else:
            print("No previous execution found.")
        ```
    """
    query = "SELECT last_successful_execution FROM core_last_successful_task_execution WHERE application_name LIKE :application_name AND job_id LIKE :job_id"
    params = {"application_name": application_name, "job_id": job_id}
    with platform_conn_engine.connect() as conn:
        res = conn.execute(text(query), params)
        if res.rowcount > 1:
            raise ValueError(
                "More than one row found in query to core_last_successful_task_execution"
            )
        if res.rowcount == 0:
            return None
        last_executed: datetime.datetime = res.fetchone()[0]
        return last_executed.astimezone(UTC_TIMEZONE)

load_data_with_caching(db_engine, table_name, query, params, force_reload)

Loads data from a database with caching support.

If caching is enabled and the table has been previously loaded, it returns the cached DataFrame. Otherwise, it fetches the data from the database.

Parameters:

Name	Type	Description	Default
db_engine	Engine	The database engine.	required
table_name	str	The name of the table being queried.	required
query	str	The SQL query to execute.	required
params	dict	Query parameters.	required
force_reload	bool	If True, forces data reloading instead of using cache.	required

Returns:

Type	Description
DataFrame	pd.DataFrame: A pandas DataFrame containing the query results.

Example

from physical_operations_utils.sql_utils import load_data_with_caching
from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

conn = get_db_connection(f"common_trading_data_{environment}")
query = "SELECT * FROM my_table WHERE date = :date"
params = {"date": "2024-02-01"}

df = load_data_with_caching(conn.engine, "my_table", query, params, force_reload=False)
print(df.head())

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(5),
)
def load_data_with_caching(
    db_engine: Engine,
    table_name: str,
    query: str,
    params: dict,
    force_reload: bool,
) -> pd.DataFrame:
    """
    Loads data from a database with caching support.

    If caching is enabled and the table has been previously loaded, it returns
    the cached DataFrame. Otherwise, it fetches the data from the database.

    Args:
        db_engine (sqlalchemy.engine.Engine): The database engine.
        table_name (str): The name of the table being queried.
        query (str): The SQL query to execute.
        params (dict): Query parameters.
        force_reload (bool): If True, forces data reloading instead of using cache.

    Returns:
        pd.DataFrame: A pandas DataFrame containing the query results.

    Example:
        ```python
        from physical_operations_utils.sql_utils import load_data_with_caching
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

        conn = get_db_connection(f"common_trading_data_{environment}")
        query = "SELECT * FROM my_table WHERE date = :date"
        params = {"date": "2024-02-01"}

        df = load_data_with_caching(conn.engine, "my_table", query, params, force_reload=False)
        print(df.head())
        ```
    """
    if force_reload or table_name not in _TABLE_TO_DATA_MAP:
        _TABLE_TO_DATA_MAP[table_name] = pandas_read_sql_with_retry(
            db_engine=db_engine, query=query, params=params
        )
    return _TABLE_TO_DATA_MAP[table_name].copy(deep=True)

log_task_execution(platform_conn_engine, application_name, job_id, comment=None)

Record the last successful execution timestamp (and optional comment) of a scheduled task into the core_last_successful_task_execution table.

This function builds a single-row pandas DataFrame containing: - application_name and job_id to identify the task, - an optional free-text comment, - last_successful_execution set to the current Stockholm time (with timezone). It then upserts that row into SQL Server using upsert_into_mssql, matching on (application_name, job_id).

Parameters:

Name	Type	Description	Default
platform_conn_engine	Engine	SQLAlchemy Engine connected to the platform database.	required
application_name	str	The name of the application or schema (e.g. "nomination").	required
job_id	str	A unique identifier for the task (e.g. "monitor variable checker").	required
comment	str | None	An optional note or comment about this execution. Defaults to None.	None

Returns:

Type	Description
None	None

Raises:

Type	Description
OperationalError	If the upsert fails at the database level and is not recoverable.
ValueError	If the DataFrame or key columns are malformed.

Example

log_task_execution(
    platform_conn_engine=engine,
    application_name="nomination",
    job_id="monitor variable checker",
    comment="Ran via cron every 5 minutes"
)

Source code in physical_operations_utils/sql_utils.py

def log_task_execution(
    platform_conn_engine: Engine,
    application_name: str,
    job_id: str,
    comment: str | None = None,
) -> None:
    """
    Record the last successful execution timestamp (and optional comment) of a scheduled task
    into the `core_last_successful_task_execution` table.

    This function builds a single-row pandas DataFrame containing:
    - `application_name` and `job_id` to identify the task,
    - an optional free-text `comment`,
    - `last_successful_execution` set to the current Stockholm time (with timezone).
    It then upserts that row into SQL Server using `upsert_into_mssql`, matching on
    (`application_name`, `job_id`).

    Parameters:
        platform_conn_engine (sqlalchemy.Engine):
            SQLAlchemy Engine connected to the platform database.
        application_name (str):
            The name of the application or schema (e.g. "nomination").
        job_id (str):
            A unique identifier for the task (e.g. "monitor variable checker").
        comment (str | None, optional):
            An optional note or comment about this execution. Defaults to None.

    Returns:
        None

    Raises:
        sqlalchemy.exc.OperationalError:
            If the upsert fails at the database level and is not recoverable.
        ValueError:
            If the DataFrame or key columns are malformed.

    Example:
        ```python
        log_task_execution(
            platform_conn_engine=engine,
            application_name="nomination",
            job_id="monitor variable checker",
            comment="Ran via cron every 5 minutes"
        )
        ```
    """
    now = get_utc_now_custom_precision()

    log = pd.DataFrame(
        {
            "application_name": [application_name],
            "job_id": [job_id],
            "comment": [comment],
            "last_successful_execution": [now],
        }
    )

    upsert_into_mssql(
        db_connection_engine=platform_conn_engine,
        df=log,
        table_name="core_last_successful_task_execution",
        column_names=[
            "application_name",
            "job_id",
            "last_successful_execution",
            "comment",
        ],
        key_columns=["job_id"],
    )
    logging.warning("Task execution timestamps logged successfully.")

pandas_read_sql_with_retry(db_engine, query, params=None)

Executes an SQL query with automatic retry on operational failures making 5 attempts with 2 seconds wait between attempts.

Parameters:

Name	Type	Description	Default
db_engine	Engine	A SQLAlchemy database Engine instance.	required
query	str	The SQL query to execute.	required
params	dict	Dictionary of query parameters.	None

Returns:; pd.DataFrame: A pandas DataFrame containing the query result.

Raises:

Type	Description
OperationalError	There is an error in the SQL statement.

Example

from physical_operations_utils.sql_utils import pandas_read_sql_with_retry
from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

ctd_conn = get_db_connection(f"common_trading_data_{environment}")

params={"variable_id": "SE3", "resolution_seconds": 900}
query = "SELECT * FROM my_table WHERE variable_id = :variable_id AND resolution_seconds = :resolution_seconds"

df = pandas_read_sql_with_retry(ctd_conn.engine, query, params)
print(df.head())

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(3),
    before=before_log(logger, logging.DEBUG),
    after=after_log(logger, logging.ERROR),
)
def pandas_read_sql_with_retry(
    db_engine: Engine, query: str, params: dict = None
) -> pd.DataFrame:
    """
    Executes an SQL query with automatic retry on operational failures making 5 attempts with 2 seconds wait between attempts.

    Parameters:
        db_engine (Engine): A SQLAlchemy database Engine instance.
        query (str): The SQL query to execute.
        params (dict, optional): Dictionary of query parameters.
    Returns:;
        pd.DataFrame: A pandas DataFrame containing the query result.

    Raises:
        OperationalError: There is an error in the SQL statement.

    Example:
        ```python
        from physical_operations_utils.sql_utils import pandas_read_sql_with_retry
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

        ctd_conn = get_db_connection(f"common_trading_data_{environment}")

        params={"variable_id": "SE3", "resolution_seconds": 900}
        query = "SELECT * FROM my_table WHERE variable_id = :variable_id AND resolution_seconds = :resolution_seconds"

        df = pandas_read_sql_with_retry(ctd_conn.engine, query, params)
        print(df.head())
        ```
    """
    params = params or {}

    try:
        with db_engine.connect() as connection:
            return pd.read_sql(text(query), connection, params=params)
    except OperationalError as e:
        logging.error(f"OperationalError: {e}")
        logging.error(f"Original exception: {e.orig}")
        logging.error(f"Arguments: {e.orig.args}")
        raise e

upsert_into_mssql(db_connection_engine, df, table_name, column_names, key_columns)

Performs an upsert (merge) of a pandas DataFrame into a Microsoft SQL Server table with automatic retries (5 retries with 2 second wait).

This function takes a DataFrame and attempts to insert or update rows in the specified table based on the provided key columns. The SQL query is constructed using parameterized bindings to prevent SQL injection, and column and table identifiers are validated before query generation. If the DataFrame is large, it is split into chunks to prevent exceeding parameter or query limits. The chunk size depends on the number of columns. A single transaction is used for all chunks to ensure atomicity, and operational failures are retried up to 5 times with a fixed delay between attempts.

The function returns the total number of rows affected across all chunks, as reported by the database.

Parameters:

Name	Type	Description	Default
db_connection_engine	Engine	A SQLAlchemy Engine object as contained in AzureSqlConnection objects.	required
df	DataFrame	The pandas DataFrame containing data to upsert.	required
table_name	str	The name of the target SQL Server table.	required
column_names	list	List of column names to be inserted or updated.	required
key_columns	list	List of column names used to determine matches (i.e., primary or unique keys).	required

Returns:

Name	Type	Description
int	int	The total number of rows affected by the upsert operation.

Raises:

Type	Description
OperationalError	Raised when an error occurs during SQL execution that is not recoverable after retries.
ValueError	Raised when the input table or column names are invalid.

Example

from physical_operations_utils.sql_utils import upsert_into_mssql
from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

df = pd.DataFrame({"id": [1, 2], "value": ["A", "B"]})

affected = upsert_into_mssql(
    db_connection=get_db_connection(f"common_trading_data_{environment}").engine,
    df=df,
    table_name="my_table",
    column_names=["id", "value"],
    key_columns=["id"]
)

print(f"{affected} rows affected.")

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(3),
    before=before_log(logger, logging.DEBUG),
    after=after_log(logger, logging.ERROR),
)
def upsert_into_mssql(
    db_connection_engine: Engine,
    df: pd.DataFrame,
    table_name: str,
    column_names: list,
    key_columns: list,
) -> int:
    """
    Performs an upsert (merge) of a pandas DataFrame into a Microsoft SQL Server table with automatic retries (5 retries with 2 second wait).

    This function takes a DataFrame and attempts to insert or update rows in the specified table based on the
    provided key columns. The SQL query is constructed using parameterized bindings to prevent SQL injection,
    and column and table identifiers are validated before query generation. If the DataFrame is large, it is
    split into chunks to prevent exceeding parameter or query limits. The chunk size depends on the number of columns.
    A single transaction is used for all chunks to ensure atomicity, and operational failures are retried up to 5 times
    with a fixed delay between attempts.

    The function returns the total number of rows affected across all chunks, as reported by the database.

    Parameters:
        db_connection_engine (sqlalchemy.Engine): A SQLAlchemy Engine object as contained in AzureSqlConnection objects.
        df (pd.DataFrame): The pandas DataFrame containing data to upsert.
        table_name (str): The name of the target SQL Server table.
        column_names (list): List of column names to be inserted or updated.
        key_columns (list): List of column names used to determine matches (i.e., primary or unique keys).

    Returns:
        int: The total number of rows affected by the upsert operation.

    Raises:
        OperationalError: Raised when an error occurs during SQL execution that is not recoverable after retries.
        ValueError: Raised when the input table or column names are invalid.

    Example:
        ```python
        from physical_operations_utils.sql_utils import upsert_into_mssql
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

        df = pd.DataFrame({"id": [1, 2], "value": ["A", "B"]})

        affected = upsert_into_mssql(
            db_connection=get_db_connection(f"common_trading_data_{environment}").engine,
            df=df,
            table_name="my_table",
            column_names=["id", "value"],
            key_columns=["id"]
        )

        print(f"{affected} rows affected.")
        ```
    """
    try:
        safe_table_name = _validate_identifiers(table_name)
        safe_column_names = [_validate_identifiers(col) for col in column_names]
        safe_key_columns = [_validate_identifiers(col) for col in key_columns]

        # Replace all pandas NaN with Python None to enable correct conversion to NULL in SQL query
        df = df[safe_column_names].copy(deep=True)
        # Force object dtype where needed
        for col in df.columns:
            if df[col].dtype.kind in {"f", "i", "M"}:  # float, int, datetime
                df[col] = df[col].astype(object)
        df = df.where(pd.notnull(df), None)

        if df.empty:
            return

        # Calculate maximum chunk size based on the number of columns to avoid exceeding SQL Server's parameter limit (2100 parameters per query)
        chunk_size = min(500, max(1, 2000 // len(column_names)))

        affected_rows = 0
        with db_connection_engine.begin() as conn:
            for chunk_start in range(0, len(df), chunk_size):
                chunk_df = df.iloc[chunk_start : chunk_start + chunk_size]
                values = chunk_df[safe_column_names].values.tolist()
                if not values:
                    continue

                merge_sql, all_params = _generate_merge_query_and_parameters(
                    table_name=safe_table_name,
                    column_names=safe_column_names,
                    key_columns=safe_key_columns,
                    values=values,
                )

                result = conn.execute(text(merge_sql), all_params)
                affected_rows += result.rowcount or 0
        return affected_rows

    except OperationalError as e:
        logging.error(f"OperationalError: {e}")
        logging.error(f"Original exception: {e.orig}")
        logging.error(f"Arguments: {e.orig.args}")
        raise e

write_to_application_log(platform_conn_engine, application_name, job_id, messages, print_log=False)

Writes a list of log messages to the core application log table with automatic retry on operational failures.

This function inserts one row per message into the core_application_log table in the physical_trading_platform_django database. Each row includes the application name, job ID, log message, and a UTC timestamp. The function uses parameterized SQL to safely insert values, and retries the entire operation up to 3 times in case of transient operational errors.

The function returns the total number of rows successfully inserted.

Parameters:

Name	Type	Description	Default
platform_conn_engine	Engine	A SQLAlchemy Engine object for the platform database.	required
application_name	str	The name of the application writing to the log.	required
job_id	str	A unique identifier for the job or task writing the log.	required
messages	List[str]	A list of log messages to write.	required
print_log	bool	A flag to determine if log messages are printed using logging.warning. Defaults to False.	False

Returns:

Name	Type	Description
int	int	The total number of rows written to the log table.

Raises:

Type	Description
OperationalError	Raised when a database error occurs that is not resolved after 3 retry attempts.

Example

from physical_operations_utils.sql_utils import upsert_into_mssql
from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

row_count = write_to_application_log(
    platform_conn_engine=get_db_connection(f"physical_trading_platform_django_{environment}").engine,
    application_name="my_pipeline",
    job_id="job_20250328_xyz",
    messages=["Job started", "Job finished successfully"],
    print_log=True,
)

print(f"{row_count} log entries inserted.")

Source code in physical_operations_utils/sql_utils.py

@retry(
    wait=wait_fixed(2),
    stop=stop_after_attempt(3),
)
def write_to_application_log(
    platform_conn_engine: Engine,
    application_name: str,
    job_id: str,
    messages: List[str],
    print_log: bool = False,
) -> int:
    """
    Writes a list of log messages to the core application log table with automatic retry on operational failures.

    This function inserts one row per message into the `core_application_log` table in the physical_trading_platform_django database.
    Each row includes the application name, job ID, log message, and a UTC timestamp. The function uses
    parameterized SQL to safely insert values, and retries the entire operation up to 3 times in case of
    transient operational errors.

    The function returns the total number of rows successfully inserted.

    Parameters:
        platform_conn_engine (Engine): A SQLAlchemy Engine object for the platform database.
        application_name (str): The name of the application writing to the log.
        job_id (str): A unique identifier for the job or task writing the log.
        messages (List[str]): A list of log messages to write.
        print_log (bool): A flag to determine if log messages are printed using logging.warning. Defaults to False.

    Returns:
        int: The total number of rows written to the log table.

    Raises:
        OperationalError: Raised when a database error occurs that is not resolved after 3 retry attempts.

    Example:
        ```python
        from physical_operations_utils.sql_utils import upsert_into_mssql
        from physical_operations_utils.azure_utils.azure_sql_connection import get_db_connection

        row_count = write_to_application_log(
            platform_conn_engine=get_db_connection(f"physical_trading_platform_django_{environment}").engine,
            application_name="my_pipeline",
            job_id="job_20250328_xyz",
            messages=["Job started", "Job finished successfully"],
            print_log=True,
        )

        print(f"{row_count} log entries inserted.")
        ```
    """
    if print_log:
        for msg in messages:
            logging.warning(msg)
    try:
        query_text = text(
            """
        INSERT INTO core_application_log (
            application_name,
            job_id,
            message,
            db_updated_utc
        ) VALUES (
            :application_name,
            :job_id,
            :message,
            :db_updated_utc
        );"""
        )
        row_count = 0
        with platform_conn_engine.connect() as conn:
            for message in messages:
                params = {
                    "application_name": application_name,
                    "job_id": job_id,
                    "message": message,
                    "db_updated_utc": get_utc_now_custom_precision(),
                }
                result = conn.execute(query_text, parameters=params)
                row_count += result.rowcount or 0
            conn.commit()
        return row_count
    except OperationalError as e:
        logging.error(f"OperationalError: {e}")
        logging.error(f"Original exception: {e.orig}")
        logging.error(f"Arguments: {e.orig.args}")
        raise e