docs(notes): update IBM DB2 table SQL guide

Author: lzwjava

Diff for: notes/2025-04-09-ibm-db2-table-sql-en.md

@@ -92,4 +92,83 @@ if __name__ == "__main__":
 - **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?
+Would you like further customization or assistance with any part of this script?
+
+---
+
+If you can use DBeaver to export the table structure to a JSON file, you can then use that JSON file to construct the `CREATE TABLE` SQL statement. Here's how you can achieve this:
+
+### Steps to Export Table Structure to JSON using DBeaver
+
+1. **Open DBeaver**: Connect to your IBM Db2 database.
+2. **Navigate to the Table**: Find the table whose structure you want to export.
+3. **Export as JSON**: Right-click on the table and select the option to export the table structure as JSON. Save the JSON file to your local machine.
+
+### Python Script to Construct `CREATE TABLE` SQL from JSON
+
+Once you have the JSON file, you can use the following Python script to read the JSON file and construct the `CREATE TABLE` SQL statement:
+
+```python
+import json
+
+def generate_create_table_sql_from_json(json_file_path):
+    # Load the JSON file
+    with open(json_file_path, 'r') as file:
+        table_data = json.load(file)
+
+    # Extract table and schema name
+    schema_name = table_data.get('schema')
+    table_name = table_data.get('name')
+
+    # Start constructing the CREATE TABLE statement
+    create_table_sql = f"CREATE TABLE {schema_name}.{table_name} (\n"
+
+    # Iterate over columns to construct the column definitions
+    for column in table_data.get('columns', []):
+        colname = column.get('name')
+        typename = column.get('type')
+        length = column.get('length')
+        scale = column.get('scale')
+        nulls = 'NOT NULL' if column.get('nullable') == False else 'NULL'
+        default = f"DEFAULT {column.get('default')}" if column.get('default') else ''
+        identity = 'GENERATED ALWAYS AS IDENTITY' if column.get('identity') == True 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"
+
+    # 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__":
+    json_file_path = 'path_to_your_json_file.json'
+    create_table_sql = generate_create_table_sql_from_json(json_file_path)
+    print(create_table_sql)
+```
+
+### Instructions
+
+1. **Export JSON**: Use DBeaver to export the table structure to a JSON file.
+2. **Update File Path**: In the script, update the `json_file_path` variable with the path to your exported JSON file.
+3. **Run the Script**: Execute the script to generate the `CREATE TABLE` SQL statement.
+
+### Additional Considerations
+
+- **JSON Structure**: Ensure the JSON file contains the necessary details such as column names, data types, lengths, scales, nullability, defaults, and identity settings.
+- **Constraints and Indexes**: If the JSON file includes information about constraints and indexes, you can extend the script to include them in the `CREATE TABLE` statement.
+
+Would you like further customization or assistance with any part of this process?