Want to check a database or a table in database exists or not??

@sumit007 asked for logic that inserts into an existing table when its columns match, or creates a new table otherwise. @Member#120589 and @network18 pointed to basic create-and-insert and form workflows, but those do not verify column compatibility. A reliable approach is to read the server metadata, compare the existing table definition to the expected columns, then decide to insert, alter, or create.

Query INFORMATION_SCHEMA.COLUMNS to get the current column list and types, then compare that result in your application to the expected schema. Example queries:

SELECT COLUMN_NAME, DATA_TYPE, COLUMN_TYPE, IS_NULLABLE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'your_db' AND TABLE_NAME = 'your_table'
ORDER BY ORDINAL_POSITION;

SELECT COUNT(*) AS matched
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'your_db' AND TABLE_NAME = 'your_table'
  AND COLUMN_NAME IN ('col1','col2','col3');

If the matched count equals the number of expected columns, inspect COLUMN_TYPE/DATA_TYPE for type compatibility before inserting. If columns are missing, choose one of: ALTER the table to add missing columns (careful with existing data), or create a new versioned table and insert there. In concurrent environments, handle the race where two processes try to create the same table—catch the duplicate-table error and re-check metadata. Always validate and whitelist any dynamic table or column names (never interpolate raw user input), use parameterized queries, and ensure the DB user has appropriate privileges.

For long-term maintainability, consider using a single table with a dataset identifier or a JSON column instead of creating many dynamic tables. See the MySQL INFORMATION_SCHEMA documentation for details: MySQL INFORMATION_SCHEMA.