mysql使用sql語句查詢數據庫全部表註釋已經表字段註釋

場景：

1. 要查詢數據庫 "mammothcode" 下全部表名以及表註釋

/* 查詢數據庫 ‘mammothcode’ 全部表註釋 */
SELECT TABLE_NAME,TABLE_COMMENT FROM information_schema.TABLES WHERE table_schema='mammothcode';

 

2. 要查詢表字段的註釋

/* 查詢數據庫 ‘mammothcode’ 下表 ‘t_adminuser’ 全部字段註釋 */
SELECT COLUMN_NAME,column_comment FROM INFORMATION_SCHEMA.Columns WHERE table_name='t_adminuser' AND table_schema='mammothcode'

 

3. 一次性查詢數據庫 "mammothcode" 下表註釋以及對應表字段註釋

SELECT t.TABLE_NAME,t.TABLE_COMMENT,c.COLUMN_NAME,c.COLUMN_TYPE,c.COLUMN_COMMENT FROM information_schema.TABLES t,INFORMATION_SCHEMA.Columns c WHERE c.TABLE_NAME=t.TABLE_NAME AND t.`TABLE_SCHEMA`='mammothcode'

 

 

擴展：使用存儲過程，對上面sql語句進行存儲，sql以下：

DELIMITER//  
DROP PROCEDURE IF EXISTS findComment//
CREATE PROCEDURE findComment (dbName VARCHAR(50))
BEGIN  
   DECLARE stmt VARCHAR(65535);  
   #若是用戶名長度大於0
   IF LENGTH(dbName)>0 THEN
     BEGIN
       SET @sqlstr=CONCAT('SELECT t.TABLE_NAME,t.TABLE_COMMENT,c.COLUMN_NAME,c.COLUMN_TYPE,c.COLUMN_COMMENT FROM information_schema.TABLES t,INFORMATION_SCHEMA.Columns c WHERE c.TABLE_NAME=t.TABLE_NAME AND t.`TABLE_SCHEMA`=','''',dbName,'''');
      END;
   ELSE
     BEGIN
      SET @sqlstr=CONCAT('SELECT ','''','數據庫名不能爲空','''', 'AS ','''','提示','''');
     END;
     END IF;
   PREPARE stmt FROM @sqlstr;
   EXECUTE stmt;
END//
DELIMITER ;

調用存儲過程：

CALL findComment('xiyinli_test');

 

上面的存儲過程還能夠簡化：在存儲過程當中直接查詢當前使用的數據庫，以下：

DELIMITER//  
DROP PROCEDURE IF EXISTS findComment//
CREATE PROCEDURE findComment ()
BEGIN  
   DECLARE stmt VARCHAR(65535);  
   #查詢當前的 use-->database
   SET @dbName=(SELECT DATABASE());
     BEGIN
       SET @sqlstr=CONCAT('SELECT t.TABLE_NAME,t.TABLE_COMMENT,c.COLUMN_NAME,c.COLUMN_TYPE,c.COLUMN_COMMENT FROM information_schema.TABLES t,INFORMATION_SCHEMA.Columns c WHERE c.TABLE_NAME=t.TABLE_NAME AND t.`TABLE_SCHEMA`=','''',@dbName,'''');
      END;
   PREPARE stmt FROM @sqlstr;
   EXECUTE stmt;
END//
DELIMITER ;

調用：

CALL findComment();