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Table of Contents
? Check if a Database Exists
? Check if a Table Exists
? Notes
Home Database Mysql Tutorial How to check if a table or database exists in MySQL?

昆仑鸿星冰球训练营成功举办 为2022北京冬奥练兵

Aug 03, 2025 am 11:19 AM
mysql 数据库检查

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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.

How to check if a table or database exists in MySQL?

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.

How to check if a table or database exists in MySQL?

? 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.

How to check if a table or database exists in MySQL?
  • 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:

How to check if a table or database exists in MySQL?
 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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