mysql升级表结构的存储过程
DROP PROCEDURE IF EXISTS add_field; CREATE PROCEDURE add_field(db_name VARCHAR(50),table_name VARCHAR(50),field_name VARCHAR(50),data_type VARCHAR(50),allow_null VARCHAR(50)) BEGIN DECLARE m_count int DEFAULT 0; DECLARE v_sql VARCHAR(500); SET v_sql= CONCAT_WS( ' ','alter table ',table_name,' add ',field_name,data_type,allow_null); #whether the table has this filed SELECT count(*) INTO m_count FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = db_name AND TABLE_NAME = table_name AND COLUMN_NAME = field_name; #if does't has this filed,then add it IF(m_count=0)THEN SET @sqlcmd = v_sql; PREPARE stmt FROM @sqlcmd; EXECUTE stmt; DEALLOCATE PREPARE stmt; END IF; END; call add_field('dbname','tablename','fieldname','DATETIME','not null');
欢迎大家阅读《mysql晋级表结构的存储过程》,跪求各位点评，by 搞代码
搞代码网（gaodaima.com）提供的所有资源部分来自互联网，如果有侵犯您的版权或其他权益，请说明详细缘由并提供版权或权益证明然后发送到邮箱[email protected]，我们会在看到邮件的第一时间内为您处理，或直接联系QQ：872152909。本网站采用BY-NC-SA协议进行授权
转载请注明原文链接：mysql晋级表结构的存储过程
转载请注明原文链接：mysql晋级表结构的存储过程
