如何查看我的数据库是否有索引?

如果是特定的桌子呢?


当前回答

如果我们知道下面的索引名,我们可以直接看到表上的索引:

Select * from all_indexes where index_name= 'your index'

其他回答

我提出这样的质疑:

SELECT DISTINCT s.*
FROM INFORMATION_SCHEMA.STATISTICS s
LEFT OUTER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS t 
    ON t.TABLE_SCHEMA = s.TABLE_SCHEMA 
       AND t.TABLE_NAME = s.TABLE_NAME
       AND s.INDEX_NAME = t.CONSTRAINT_NAME 
WHERE 0 = 0
      AND t.CONSTRAINT_NAME IS NULL
      AND s.TABLE_SCHEMA = 'YOUR_SCHEMA_SAMPLE';

您已找到所有索引索引。

把。

查询数据库中所有已禁用的索引

SELECT INDEX_SCHEMA, COLUMN_NAME, COMMENT 
FROM information_schema.statistics
WHERE table_schema = 'mydb'
AND COMMENT = 'disabled'

如果你想一次性查看所有数据库的所有索引:

use information_schema;
SELECT * FROM statistics;

按顺序获取一列中每个索引的所有索引列。

SELECT table_name AS `Table`,
       index_name AS `Index`,
       GROUP_CONCAT(column_name ORDER BY seq_in_index) AS `Columns`
FROM information_schema.statistics
WHERE table_schema = 'sakila'
GROUP BY 1,2;

裁判:http://blog.9minutesnooze.com/mysql-information-schema-indexes/

SHOW INDEX FROM mytable FROM mydb;

SHOW INDEX FROM mydb.mytable;

见文档。