IBM Db2 Table SQL

IBM Db2 Table SQL | Generated by AI

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Certainly! Below is a Python script that generates a CREATE TABLE SQL statement for an existing table in IBM Db2. This script assumes you have access to the Db2 database and can execute SQL queries to retrieve the necessary metadata.

Python Script to Generate `CREATE TABLE` SQL

import ibm_db

def generate_create_table_sql(schema_name, table_name, conn):
    # Query to get column details
    query = f"""
    SELECT COLNAME, TYPENAME, LENGTH, SCALE, NULLS, DEFAULT, IDENTITY
    FROM SYSCAT.COLUMNS
    WHERE TABSCHEMA = '{schema_name}' AND TABNAME = '{table_name}'
    ORDER BY COLNO;
    """

    # Execute the query
    stmt = ibm_db.exec_immediate(conn, query)
    result = ibm_db.fetch_assoc(stmt)

    # Start constructing the CREATE TABLE statement
    create_table_sql = f"CREATE TABLE {schema_name}.{table_name} (\n"

    while result:
        colname = result['COLNAME']
        typename = result['TYPENAME']
        length = result['LENGTH']
        scale = result['SCALE']
        nulls = 'NOT NULL' if result['NULLS'] == 'N' else 'NULL'
        default = f"DEFAULT {result['DEFAULT']}" if result['DEFAULT'] else ''
        identity = 'GENERATED ALWAYS AS IDENTITY' if result['IDENTITY'] == 'Y' else ''

        # Construct the column definition
        col_def = f"    {colname} {typename}"
        if length:
            col_def += f"({length}"
            if scale:
                col_def += f", {scale}"
            col_def += ")"
        col_def += f" {nulls}"
        if default:
            col_def += f" {default}"
        if identity:
            col_def += f" {identity}"

        create_table_sql += col_def + ",\n"
        result = ibm_db.fetch_assoc(stmt)

    # Remove the last comma and add the closing parenthesis
    create_table_sql = create_table_sql.rstrip(",\n") + "\n);"

    return create_table_sql

# Example usage
if __name__ == "__main__":
    # Replace with your actual database connection details
    dsn = "DATABASE=your_db;HOSTNAME=your_host;PORT=your_port;PROTOCOL=TCPIP;UID=your_uid;PWD=your_pwd;"
    conn = ibm_db.connect(dsn, "", "")

    schema_name = 'your_schema'
    table_name = 'your_table'

    create_table_sql = generate_create_table_sql(schema_name, table_name, conn)
    print(create_table_sql)

    # Close the connection
    ibm_db.close(conn)

Instructions

Install IBM Db2 Driver: Ensure you have the IBM Db2 driver installed. You can install it using pip:
```
pip install ibm_db
```
Database Connection: Update the dsn variable with your actual database connection details.
Run the Script: Execute the script to generate the CREATE TABLE SQL statement for the specified table.

Additional Considerations

Constraints and Indexes: This script does not include primary keys, foreign keys, or indexes. You would need to query additional system catalog tables to retrieve this information and add it to the CREATE TABLE statement.
Error Handling: Add error handling as needed to manage database connection issues or query execution errors.

Would you like further customization or assistance with any part of this script?

To integrate the ibm_db_dbi package into your script, you can use it to establish a connection and execute queries. The ibm_db_dbi package provides a more Pythonic interface for interacting with IBM Db2 databases, similar to other DB-API 2.0 compliant modules like sqlite3 or psycopg2.

Here’s how you can modify your script to use ibm_db_dbi:

import ibm_db
import ibm_db_dbi

def generate_create_table_sql(schema_name, table_name, conn):
    # Query to get column details
    query = f"""
    SELECT COLNAME, TYPENAME, LENGTH, SCALE, NULLS, DEFAULT, IDENTITY
    FROM SYSCAT.COLUMNS
    WHERE TABSCHEMA = '{schema_name}' AND TABNAME = '{table_name}'
    ORDER BY COLNO;
    """

    # Execute the query using ibm_db_dbi
    cursor = conn.cursor()
    cursor.execute(query)
    result = cursor.fetchone()

    # Start constructing the CREATE TABLE statement
    create_table_sql = f"CREATE TABLE {schema_name}.{table_name} (\n"

    while result:
        colname = result[0]
        typename = result[1]
        length = result[2]
        scale = result[3]
        nulls = 'NOT NULL' if result[4] == 'N' else 'NULL'
        default = f"DEFAULT {result[5]}" if result[5] else ''
        identity = 'GENERATED ALWAYS AS IDENTITY' if result[6] == 'Y' else ''

        # Construct the column definition
        col_def = f"    {colname} {typename}"
        if length:
            col_def += f"({length}"
            if scale:
                col_def += f", {scale}"
            col_def += ")"
        col_def += f" {nulls}"
        if default:
            col_def += f" {default}"
        if identity:
            col_def += f" {identity}"

        create_table_sql += col_def + ",\n"
        result = cursor.fetchone()

    # Remove the last comma and add the closing parenthesis
    create_table_sql = create_table_sql.rstrip(",\n") + "\n);"

    return create_table_sql

# Example usage
if __name__ == "__main__":
    # Replace with your actual database connection details
    dsn = "DATABASE=your_db;HOSTNAME=your_host;PORT=your_port;PROTOCOL=TCPIP;UID=your_uid;PWD=your_pwd;"
    conn = ibm_db_dbi.connect(dsn, "", "")

    schema_name = 'your_schema'
    table_name = 'your_table'

    create_table_sql = generate_create_table_sql(schema_name, table_name, conn)
    print(create_table_sql)

    # Close the connection
    conn.close()

Key Changes:

Connection: The connection is established using ibm_db_dbi.connect() instead of ibm_db.connect().
Cursor: A cursor is created using conn.cursor(), and queries are executed using this cursor.
Fetching Results: Results are fetched using cursor.fetchone(), which returns a tuple.

This approach leverages the ibm_db_dbi package for a more Pythonic way of interacting with the database, making the code cleaner and easier to manage.

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IBM Db2 Table SQL | Generated by AI

Python Script to Generate CREATE TABLE SQL

Instructions

Additional Considerations

Key Changes:

Python Script to Generate `CREATE TABLE` SQL