如何从同一表名中的值更新表列名？

Question

  eid   |        ename          |    fname       midname  |   lname
--------+-----------------------+-------------+-----------+---------- 
   1            hansen
   2          hansen ola
   3       dennis richard hog

现在如何将它们更新为这样：

  eid   |        ename          |    fname       midname  |   lname
--------+-----------------------+-------------+-----------+---------- 
   1             hansen
   2           hansen ola            hansen        ola
   3       dennis richsard hog       dennis      richard       hog

Answer 1

只需从表中获取ename并使用explode(' ', $name)或str_word_count ($name, 1)将其分解为名字，中间名和姓氏str_word_count ($name, 1)然后相应地更新表。

用于选择行的SQL：

SELECT * FROM <tablename>

用于更新行的SQL：

UPDATE <tablename> SET <columnname> = <value> WHERE ename = <ename>

Answer 2

如果名称始终相同，则可以使用str_word_count ： str_word_count ($ result, 1)来简单地检索数组中字符串的单词。

它有助于您还是您希望我发展？

Answer 3

嗨，请检查下面的SQL代码以获取更新语句。

CREATE TABLE emptble(eid int,ename varchar(200) NULL,fname varchar(50) NULL,midname varchar(25) NULL,lname varchar(100) NULL)

INSERT INTO emptble(eid,ename)
VALUES(1,'hansen'),(2,'hansen ola'),(3,'dennis richard hog')

SELECT ename,
       CASE WHEN CHARINDEX(' ',ename,1)>0 then LEFT(ename,CHARINDEX(' ',ename,1)-1) ELSE ename END,
       CASE WHEN CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1)>0 THEN LEFT((CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1)-1) ELSE (CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END) END,
       CASE WHEN CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1) = 0 THEN NULL ELSE RIGHT(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END,LEN(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END)-CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1)) END


FROM emptble

UPDATE emptble SET fname= CASE WHEN CHARINDEX(' ',ename,1)>0 then LEFT(ename,CHARINDEX(' ',ename,1)-1) ELSE ename END,
                   midname =CASE WHEN CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1)>0 THEN LEFT((CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1)-1) ELSE (CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END) END,
                   lname=CASE WHEN CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1) = 0 THEN NULL ELSE RIGHT(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END,LEN(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END)-CHARINDEX(' ',(CASE WHEN CHARINDEX(' ',ename,1) = 0 then NULL ELSE RIGHT(ename,len(ename)-CHARINDEX(' ',ename,1)) END),1)) END



SELECT * FROM emptble