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Add index to table if it doesn't exist

I want to add an index to a table using syntax ALTER

, and I also want to check if the index exists on the table, and if it doesn't exist, add the index.

 ALTER TABLE tableName ADD INDEX IX_Table_XYZ (column1);

Is there a way to do this?

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2 answers


Try it like this:



set @x := (select count(*) from information_schema.statistics where table_name = 'table' and index_name = 'IX_Table_XYZ' and table_schema = database());
set @sql := if( @x > 0, 'select ''Index exists.''', 'Alter Table TableName ADD Index IX_Table_XYZ (column1);');
PREPARE stmt FROM @sql;
EXECUTE stmt;
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You can check if an index exists (by index name) with this syntax

SELECT 1        
FROM INFORMATION_SCHEMA.STATISTICS
WHERE TABLE_SCHEMA = 'yourschema' AND TABLE_NAME='yourtable' AND
INDEX_NAME='yourindex';


Then you can run it in a stored procedure like

IF (SELECT 1        
    FROM INFORMATION_SCHEMA.STATISTICS
    WHERE TABLE_SCHEMA = 'yourschema' AND TABLE_NAME='yourtable' AND
    INDEX_NAME='yourindex') != 1 THEN

Alter Table TableName ADD Index IX_Table_XYZ (column1);

END IF;
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