从join on和where执行顺序认识T-SQL查询处理执行顺序

先从一例子看join on 和 where执行结果的不同

CREATE TABLE "SCOTT"."A" (

"PERSON_ID" NUMBER(5) NULL ,

"PERSON_NAME" VARCHAR2(255 BYTE) NULL 

)

;

-- ----------------------------

-- Records of A

-- ----------------------------

INSERT INTO "SCOTT"."A" VALUES ('1', '张三');

INSERT INTO "SCOTT"."A" VALUES ('2', '李四');

INSERT INTO "SCOTT"."A" VALUES ('3', '王五');

INSERT INTO "SCOTT"."A" VALUES ('4', '赵六');

INSERT INTO "SCOTT"."A" VALUES ('5', '周七');

CREATE TABLE "SCOTT"."B" (

"PERSON_ID" NUMBER(5) NULL ,

"LOVE_FRUIT" VARCHAR2(255 BYTE) NULL 

);

-- ----------------------------

-- Records of B

-- ----------------------------

INSERT INTO "SCOTT"."B" VALUES ('1', '香蕉');

INSERT INTO "SCOTT"."B" VALUES ('2', '苹果');

INSERT INTO "SCOTT"."B" VALUES ('3', '橘子');

INSERT INTO "SCOTT"."B" VALUES ('4', '梨');

INSERT INTO "SCOTT"."B" VALUES ('8', '桃');

View Code