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  • 一次mysql数据关于union+concat用法的记录

        SELECT CONCAT('SELECT COUNT(*)  FROM ',table_name,' union all') 
        FROM information_schema.tables WHERE table_name LIKE 'tbl_sms_bill_1806%'
        INTO OUTFILE '/tmp/full06.sql';
        
        
        SELECT CONCAT('SELECT COUNT(*)  FROM ',table_name,' union') 
        FROM information_schema.tables WHERE table_name LIKE 'tbl_sms_bill_1808%'
        INTO OUTFILE '/tmp/full08.sql';
        
        SELECT CONCAT('SELECT COUNT(*)  FROM ',table_name,' union') 
        FROM information_schema.tables WHERE table_name LIKE 'tbl_sms_bill_1809%'
        INTO OUTFILE '/tmp/full09.sql';
        
        
        
        SELECT CONCAT('SELECT COUNT(*)  FROM ',table_name,' WHERE stat !="DELIVRD"',' union') 
        FROM information_schema.tables WHERE table_name LIKE 'tbl_sms_bill_1806%'
        INTO OUTFILE '/tmp/bak06.sql';
        
        
        SELECT CONCAT('SELECT COUNT(*)  FROM ',table_name,' WHERE stat !="DELIVRD"',' union') 
        FROM information_schema.tables WHERE table_name LIKE 'tbl_sms_bill_1808%'
        INTO OUTFILE '/tmp/bak08.sql';
        
        
        SELECT CONCAT('SELECT COUNT(*)  FROM ',table_name,' WHERE stat !="DELIVRD"',' union') 
        FROM information_schema.tables WHERE table_name LIKE 'tbl_sms_bill_1809%'
        INTO OUTFILE '/tmp/bak09.sql';

    union 去除重复值 将结果拼接

    union all 不去除重复值

    关于concat的时候  如果语句当中有引号可以用 双引号代替

    另外有的mysql版本在用concat导出是直接可以的  这个问题还要多测试

    未来肯定有更好的方法 待补充

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  • 原文地址:https://www.cnblogs.com/nodchen/p/9683939.html
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