Question

我有一个包含57k条目的表格，其中包含列comp_phone（UNIQUE KEY Phone（comp_phone））现在我尝试使用

来计算此列

update uk_data set comp_phone= REPLACE(comp_phone,'  ',' ')

但是因为我在这个列上有UNIQUE KEY我收到错误

[SQL] update uk_data set comp_phone= REPLACE(comp_phone,'  ',' ')

[Err] 1062 - Duplicate entry '01268 203***' for key 'Phone'

所以我正在使用

DELETE FROM uk_data WHERE comp_phone = '01268 203***'

删除旧行。但这需要很长时间，因为我不知道在REPLACE之后有多少行会重复，所以有一种简单的方法来替换和删除或覆盖旧条目

THX

Answer 1

测试此查询

CREATE TEMPORARY table Kratika
(
    _id int,
    _value varchar(50)
);

INSERT INTO Kratika
SELECT 1, '1111222255' UNION 
SELECT 2, '1111222 255' UNION -- duplicate
SELECT 3, '11112222 55' UNION -- duplicate
SELECT 4, '1111222233'; -- not duplicate

SELECT * FROM Kratika;

DELETE FROM Kratika WHERE _value <> REPLACE(_value, ' ', '') ;

SELECT * FROM Kratika;

<强>输出

1   1111222255
2   1111222 255
3   11112222 55
4   1111222233

-- Select after deletion of duplicate records
    1   1111222255
    4   1111222233

<强>被修改

如果你对while循环没问题那么你可以测试一下（我不是MySQL开发人员，我不知道为什么MySQL不允许我写while循环，所以创建了相同的proc）

DROP PROCEDURE IF EXISTS test_kratik;
delimiter ##

CREATE PROCEDURE test_kratik
(

)
BEGIN
DROP table IF EXISTS Kratika;
CREATE TEMPORARY table Kratika
(
    _id int,
    _value varchar(50)
);

INSERT INTO Kratika
SELECT 1, '1111222255' UNION 
SELECT 2, '1111222 255' UNION -- duplicate
SELECT 3, '11112222 55' UNION -- duplicate
SELECT 4, '1111222233'; -- not duplicate

SELECT * FROM Kratika;

SET @ID := 0;
SET @DUP_ID := 0;
SET @value := '';

WHILE @ID <= (SELECT MAX(_id) FROM kratika) DO
    BEGIN
        IF EXISTS(SELECT _id from kratika WHERE _id = @ID) THEN
            BEGIN
                SET @value = (SELECT REPLACE(_value, ' ', '') from kratika WHERE _id = @ID);
                DELETE FROM kratika
                WHERE REPLACE(_value, ' ', '') = @value
                AND _id <> @ID;
            END;
        END IF;
        SET @ID = @ID + 1;
    END;
END WHILE;

UPDATE kratika
SET _value = REPLACE(_value, ' ', '') 
WHERE _value <> REPLACE(_value, ' ', '') ;

SELECT * FROM kratika;

END ##

delimiter ;

CALL test_kratik();

已更新 如果您不想使用while循环，那就没关系....

    DROP TABLE IF EXISTS Kratika; 

CREATE TEMPORARY table Kratika
(
    _id int,
    _value varchar(50)
);

INSERT INTO Kratika
SELECT 1, '1111222255' UNION 
SELECT 2, '1111222 255' UNION -- duplicate
SELECT 3, '11112222 55' UNION -- duplicate
SELECT 4, '111122 2233'; -- not duplicate

DROP TABLE IF EXISTS copy_temp; 

CREATE TEMPORARY table copy_temp  
(
    _id1 int,
    _value1 varchar(50)
);

INSERT INTO copy_temp
SELECT _id, _value FROM kratika;

SELECT * FROM Kratika;

DELETE FROM Kratika 
WHERE _id <> (SELECT _id1 FROM copy_temp 
WHERE REPLACE(_value, ' ', '') = REPLACE(_value1, ' ', '') 
Limit 1
);

UPDATE kratika
SET _value = REPLACE(_value, ' ', '') 
WHERE _value <> REPLACE(_value, ' ', '') ;


SELECT * FROM Kratika;

<强>输出

1   1111222255
2   1111222 255
3   11112222 55
4   1111222233

更新后

1   1111222255
4   1111222233

Mysql REPLACE和删除旧条目

1 个答案: