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  • SQL相关

    列别名不能用于where子句

    动态sql,某一列值作为子查询的表名,或者某一列值为一个sql语句,直接查询结果

    内存表

    按日期分组

     select count(*),substr(t.date,1,10)  from table t where  t.date like '2010-03%' group by substr(t.date,1,10) 
     
    over开窗函数
     
    防止插入重复数据
    INSERT INTO data_group_call_link (
        groupcall_id,
        data_id,
        data_phone,
        data_source
    )(
        SELECT
            "3" groupcall_id,
            uuid data_id,
            item_phone data_phone,
            "k" data_source
        FROM
            data_item_b23209a6517c42da9f7338290a181f16
        WHERE
            NOT EXISTS (
                SELECT
                    *
                FROM
                    data_group_call_link
                WHERE
                    item_phone = data_group_call_link.data_phone
                OR item_owner IS NOT NULL
            
    )

    根据条件做count操作

    SELECT
        p.container_name DATA,
        count(t.data_source) num,
        sum(
            CASE
            WHEN t.call_flag > "0" THEN
                1
            ELSE
                0
            END
        ) complete
    FROM
        data_group_call_link t
    JOIN data_container p ON t.data_source = p.data_table
    WHERE
        t.groupcall_id = "3"
    GROUP BY
        t.data_source 
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  • 原文地址:https://www.cnblogs.com/guangshan/p/4506548.html
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