1、查看已创建了哪些索引。
show index from table_name;
2、查询表已创建的索引,并返回创建语句。
SELECT
CONCAT('ALTER TABLE `',TABLE_NAME,'` ', 'ADD ',
IF(NON_UNIQUE = 1,
CASE UPPER(INDEX_TYPE)
WHEN 'FULLTEXT' THEN 'FULLTEXT INDEX'
WHEN 'SPATIAL' THEN 'SPATIAL INDEX'
ELSE CONCAT('INDEX `',
INDEX_NAME,
'` USING ',
INDEX_TYPE
)
END,
IF(UPPER(INDEX_NAME) = 'PRIMARY',
CONCAT('PRIMARY KEY USING ',
INDEX_TYPE
),
CONCAT('UNIQUE INDEX `',
INDEX_NAME,
'` USING ',
INDEX_TYPE
)
)
),'(', GROUP_CONCAT(DISTINCT CONCAT('`', COLUMN_NAME, '`') ORDER BY SEQ_IN_INDEX ASC SEPARATOR ', '), ');') AS 'Show_Add_Indexes'
FROM information_schema.STATISTICS
WHERE TABLE_SCHEMA = 'm2o_publishcontent' and TABLE_NAME='m2o_content_client_relation_2'
GROUP BY TABLE_NAME, INDEX_NAME
ORDER BY TABLE_NAME ASC, INDEX_NAME ASC;
-- 说明:倒数第三行的where条件处 TABLE_SCHEMA 填写数据库名,TABLE_NAME 填写数据表名
-- 只需要改对应字段的值即可执行。