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To check whether the database or table exists in MySQL, use the INFORMATION_SCHEMA or SHOW command. 1. Check whether the database exists: Use SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'your_database_name'; or SHOW DATABASES LIKE 'your_database_name'; 2. Check whether the table exists: Use SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'your_database_name' AND TABLE_NAME = 'your_table_name'; or SHOW TABLES FROM your_database_name LIKE 'your_table_name'; The query returns the result to indicate that it exists, otherwise it does not exist. Both methods are safe and will not report errors. Just select the appropriate method according to the usage scenario.
To check if a table or database exists in MySQL, you can use built-in system information tables from the INFORMATION_SCHEMA
. Here's how to do it for both databases and tables.

? Check if a Database Exists
Use the INFORMATION_SCHEMA.SCHEMATA
table:
SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'your_database_name';
Replace 'your_database_name'
with the actual name you're checking.

- If a row is returned, the database exists.
- If no rows are returned, it doesn't exist.
Example:
SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'myapp_db';
You can also use:

SHOW DATABASES LIKE 'your_database_name';
This is simpler and returns matching database names.
? Check if a Table Exists
Query the INFORMATION_SCHEMA.TABLES
table:
SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'your_database_name' AND TABLE_NAME = 'your_table_name';
- Replace
'your_database_name'
with the database you're checking in. - Replace
'your_table_name'
with the table name.
Example:
SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'myapp_db' AND TABLE_NAME = 'users';
Alternatively, use:
SHOW TABLES FROM your_database_name LIKE 'your_table_name';
For example:
SHOW TABLES FROM myapp_db LIKE 'users';
This returns the table name if it exists.
? Notes
- These methods are safe and don't throw errors if the object doesn't exist.
- Case sensitivity depends on the operating system and MySQL settings (eg, on Linux, table names are case-sensitive by default).
- You need appropriate privileges to query
INFORMATION_SCHEMA
or see database/table metadata.
So, whether you prefer SQL queries or SHOW
commands, both approaches work well. Use INFORMATION_SCHEMA
for more control (especially in scripts or applications), and SHOW
for quick checks in the MySQL shell.
Basically, just pick the right query based on whether you're looking for a database or a table.
The above is the detailed content of How to check if a table or database exists in MySQL?. For more information, please follow other related articles on the PHP Chinese website!

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