联合约束 CONCAT()

w SELECT 原理。

 SELECT * FROM wz WHERE CONCAT(wint,wchar) NOT IN (SELECT CONCAT(wint,wchar) FROM wa);

 SELECT * FROM wz WHERE CONCAT(wint,wchar)     IN (SELECT CONCAT(wint,wchar) FROM wa);

 TRUNCATE wz;

 INSERT INTO wz SELECT * FROM wa WHERE id>14;

 INSERT INTO wz SELECT * FROM wb WHERE id<9;

 INSERT INTO wz SELECT * FROM we WHERE id>10 AND id<15;

 UPDATE wz SET wchar=CONCAT(wint,'wz');

 INSERT INTO wz(wint,wchar) SELECT wint,wchar FROM wa WHERE id>14;

 INSERT INTO wz(wint,wchar) SELECT wint,wchar FROM wb WHERE id<9;

 INSERT INTO wz(wint,wchar) SELECT wint,wchar FROM we WHERE id>10 AND id<15;

 UPDATE wa SET wint=id+100;

 UPDATE wa SET wint=id+4444,wchar=CONCAT(wint,'wa');

 DELETE FROM wa WHERE id>16;

 UPDATE wb SET wint=id+1000;

 UPDATE wb SET wchar=CONCAT(wint,'wb');

 DELETE FROM wb WHERE id>16;

 UPDATE we SET wint=id+10000;

 UPDATE we SET wchar=CONCAT(wint,'we');

 DELETE FROM we WHERE id>16;

id wint wchar

15 115 115wz
16116116wz
110011001wz
210021002wz
310031003wz
410041004wz
510051005wz
610061006wz
710071007wz
810081008wz
111001110011wz
121001210012wz
131001310013wz
141001410014wz
17115115wa
18116116wa
1910011001wb
2010021002wb
2110031003wb
2210041004wb
2310051005wb
2410061006wb
2510071007wb
2610081008wb
271001110011we
281001210012we
291001310013we
301001410014we