SELECT * FROM INFORMATION_SCHEMA.CHARACTER_SETS;

tables 提供表信息.

SELECT table_name, table_type, engine
       FROM information_schema.tables
       WHERE table_schema = 'test'
       ORDER BY table_name;

COLUMNS 提供表的字段信息.

SELECT COLUMN_NAME, DATA_TYPE, IS_NULLABLE, COLUMN_DEFAULT
  FROM INFORMATION_SCHEMA.COLUMNS
  WHERE table_name = 'a'
  AND table_schema = 'test';

STATISTICS 提供表的索引信息.

SELECT * FROM INFORMATION_SCHEMA.STATISTICS
  WHERE table_name = 'b'
  AND table_schema = 'test'

TRIGGERS 提供表的触发器信息.

drop TRIGGER if exists test_trigger;


CREATE TRIGGER test_trigger AFTER INSERT ON a FOR EACH ROW
BEGIN

SET @id = new.id;


SET @NAME = new. NAME;


SET @pwd = new.pwd;

UPDATE pivot
SET Author = (
    SELECT

    IF (
        @attribute = 'Author' ,@VALUE,
        Author
    )
),
 Title = (
    SELECT

    IF (
        @attribute = 'Title' ,@VALUE,
        Title
    )
),
 Publisher = (
    SELECT

    IF (
        @attribute = 'Publisher' ,@VALUE,
        Publisher
    )
)
WHERE
    id =@id;


END


SELECT * FROM INFORMATION_SCHEMA.TRIGGERS
       WHERE TRIGGER_SCHEMA='test' AND TRIGGER_NAME='test_trigger';

VIEWS 提供表的视图信息.

CREATE VIEW test.v AS SELECT 'a' || 'b' as col1;
SELECT * FROM INFORMATION_SCHEMA.VIEWS
       WHERE TABLE_SCHEMA = 'test' AND TABLE_NAME = 'v';