Mysql中索引和约束相关

SELECT
CONCAT(
'ALTER TABLE `',
TABLE_NAME,
'` ',
'MODIFY COLUMN `',
COLUMN_NAME,
'` ',
IF(UPPER(DATA_TYPE) = 'INT',
REPLACE(
SUBSTRING_INDEX(
UPPER(COLUMN_TYPE),
')',
1
),
'INT',
'INTEGER'
),
UPPER(COLUMN_TYPE)
),
') UNSIGNED NOT NULL AUTO_INCREMENT;'
)
FROM information_schema.COLUMNS
WHERE TABLE_SCHEMA = '数据库名' AND
EXTRA = UPPER('AUTO_INCREMENT')
ORDER BY TABLE_NAME ASC;

SELECT
CONCAT(
'ALTER TABLE `',
TABLE_NAME,
'` ',
'MODIFY COLUMN `',
COLUMN_NAME,
'` ',
IF(UPPER(DATA_TYPE) = 'INT',
REPLACE(
SUBSTRING_INDEX(
UPPER(COLUMN_TYPE),
')',
1
),
'INT',
'INTEGER'
),
UPPER(COLUMN_TYPE)
),
') UNSIGNED NOT NULL;'
)
FROM information_schema.COLUMNS
WHERE TABLE_SCHEMA = '数据库名' AND
EXTRA = UPPER('AUTO_INCREMENT')
ORDER BY TABLE_NAME ASC;

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 = '数据库名'
GROUP BY TABLE_NAME, INDEX_NAME
ORDER BY TABLE_NAME ASC, INDEX_NAME ASC;

SELECT
CONCAT(
'ALTER TABLE `',
TABLE_NAME,
'` ',
GROUP_CONCAT(
DISTINCT
CONCAT(
'DROP ',
IF(UPPER(INDEX_NAME) = 'PRIMARY',
'PRIMARY KEY',
CONCAT('INDEX `', INDEX_NAME, '`')
)
)
SEPARATOR ', '
),
';'
)
FROM information_schema.STATISTICS
WHERE TABLE_SCHEMA = '数据库名'
GROUP BY TABLE_NAME
ORDER BY TABLE_NAME ASC;

select TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME from INFORMATION_SCHEMA.KEY_COLUMN_USAGE
where TABLE_SCHEMA='数据库名' and REFERENCED_TABLE_NAME = '表名';

select CONCAT('ALTER TABLE ',TABLE_NAME, ' ADD CONSTRAINT ',CONSTRAINT_NAME,' FOREIGN KEY (',COLUMN_NAME,') REFERENCES ', REFERENCED_TABLE_NAME,'(',REFERENCED_COLUMN_NAME,') ON DELETE CASCADE ON UPDATE CASCADE;') from INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA='数据库名' AND  REFERENCED_TABLE_NAME IS NOT NULL;

select CONCAT('ALTER TABLE ',TABLE_NAME, ' DROP FOREIGN KEY ',CONSTRAINT_NAME,';') from INFORMATION_SCHEMA.KEY_COLUMN_USAGE
where TABLE_SCHEMA='数据库名' AND  REFERENCED_TABLE_NAME IS NOT NULL;