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oraclegroupby语句实例测试

实例测试 语句
2023-06-13 09:14:41 时间
Sql代码
复制代码代码如下:

CREATETABLEtest(aVARCHAR2(20),bVARCHAR2(20),cNUMBER,dVARCHAR2(20))

INSERTINTOtestVALUES("a1","b1",1,"t");
INSERTINTOtestVALUES("a3","b3",3,"t");
INSERTINTOtestVALUES("a4","b4",4,"t");
INSERTINTOtestVALUES("a2","b2",2,"t");
INSERTINTOtestVALUES("xx","xx",5,"x");

INSERTINTOtestVALUES("a1","b1",1,"t");
INSERTINTOtestVALUES("a3","b3",3,"t");
INSERTINTOtestVALUES("a4","b4",4,"t");
INSERTINTOtestVALUES("a2","b2",2,"t");
INSERTINTOtestVALUES("xx","xx",5,"x");
COMMIT;

1.SELECTa,b,SUM(c)FROMtestWHEREd="t"GROUPBYa,bORDERBYa,b;

2.SELECTa,b,SUM(c)FROMtestWHEREd="t"GROUPBYb,aORDERBYa,b;

总结：对于1，2而言，结果应该是一样的，但是分组的顺序不同，SQL的性能应该也是不同的。

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