Detailed usage of exists in SQL statements

Catalog

Preface

One 、 Build table

Two 、 stay SELECT Use in statement EXISTS

 1. stay SQL Use in EXISTS

 2. stay SQL Use in NOT EXISTS

 3. stay SQL Using multiple in NOT EXISTS

 4. stay SQL Using multiple in EXISTS

 5. stay SQL Use in NOT EXISTS and EXISTS

3、 ... and 、 stay DELETE Use in statement EXISTS

1. stay MySQL Use in

 2. stay Oracle Use in

Four 、 stay UPDATE Use in statement EXISTS

1. stay MySQL Use in

 2. stay Oracle Use in

summary

Preface

In the course of business , There will be similar needs .

demand 1：UPDATE surface TEST_TB01 Records in ; Meet the conditions ： These records are not in TEST_TB02 in .

demand 2：UPDATE surface TEST_TB01 Records in ; Meet the conditions ： These are recorded in TEST_TB02 in .

stay SQL In the sentence EXISTS Usage of , Can be relatively simple to solve such needs .

One 、 Build table

1. stay MySQL Database table creation statement

CREATE TABLE TEST_TB01( sensor_id BIGINT, part_id BIGINT, flag VARCHAR(64) )COMMENT ' Data sheet 1 ';CREATE TABLE TEST_TB02( sensor_id BIGINT, part_id BIGINT, flag VARCHAR(64) )COMMENT ' Data sheet II ';CREATE TABLE TEST_TB03( sensor_id BIGINT, part_id BIGINT, flag VARCHAR(64) )COMMENT ' Data sheet III ';

2. stay ORACLE Database table creation statement

CREATE TABLE TEST_TB01( sensor_id NUMBER(16), part_id NUMBER(16), flag VARCHAR(64) );CREATE TABLE TEST_TB02( sensor_id NUMBER(16), part_id NUMBER(16), flag VARCHAR(64) ); Two 、 stay SELECT Use in statement EXISTS

stay SELECT Of SQL Use in statement EXISTS.

stay TEST_TB01 insert data ：

INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2101,8811,' Xiamen ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2102,8812,' quanzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2103,8813,' fuzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2104,8814,' zhangzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2105,8815,' Hangzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2106,8816,' Shanghai ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2107,8817,' Beijing ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2108,8818,' Shenzhen ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2109,8819,' China ');

stay TEST_TB02 insert data ：

INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2101,8811,' Xiamen ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2102,8812,' quanzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2103,8813,' fuzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2104,8814,' zhangzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2109,8819,' China ');

stay TEST_TB03 insert data ：

INSERT INTO TEST_TB03 (sensor_id,part_id,flag) VALUES(2106,8816,' Shanghai ');INSERT INTO TEST_TB03 (sensor_id,part_id,flag) VALUES(2107,8817,' Beijing ');INSERT INTO TEST_TB03 (sensor_id,part_id,flag) VALUES(2109,8819,' China ');

see TEST_TB01 data ：

see TEST_TB02 data ：

see TEST_TB03 data ：

 1. stay SQL Use in EXISTS

demand ： from TEST_TB01 Find out in TEST_TB02 Records that exist in , The association condition is the of two tables sensor_id equal .

SQL sentence ：

SELECT aa.sensor_id,aa.part_id,aa.flagFROM TEST_TB01 aaWHERE EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id);

Execution results ：

 2. stay SQL Use in NOT EXISTS

demand ： from TEST_TB01 Find out in TEST_TB02 Records that do not exist in , The association condition is the of two tables sensor_id equal .

SQL sentence ：

SELECT aa.sensor_id,aa.part_id,aa.flagFROM TEST_TB01 aaWHERE NOT EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id);

Execution results ：

 3. stay SQL Using multiple in NOT EXISTS

demand ： from TEST_TB01 Find out in TEST_TB02 and TEST_TB03 Records that do not exist in , The association condition is the of the table sensor_id equal .

SQL sentence ：

SELECT aa.sensor_id,aa.part_id,aa.flagFROM TEST_TB01 aaWHERE NOT EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id) AND NOT EXISTS (SELECT 1 FROM TEST_TB03 cc WHERE aa.sensor_id = cc.sensor_id);

Execution results ：

 4. stay SQL Using multiple in EXISTS

demand ： from TEST_TB01 Find out in TEST_TB02 and TEST_TB03 Records that exist in , The association condition is the of the table sensor_id equal .

SQL sentence ：

SELECT aa.sensor_id,aa.part_id,aa.flagFROM TEST_TB01 aaWHERE EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id) AND EXISTS (SELECT 1 FROM TEST_TB03 cc WHERE aa.sensor_id = cc.sensor_id);

Execution results ：

 5. stay SQL Use in NOT EXISTS and EXISTS

demand ： from TEST_TB01 Find out in TEST_TB02 There is, but TEST_TB03 Records that do not exist in , The association condition is the of the table sensor_id equal .

SQL sentence ：

SELECT aa.sensor_id,aa.part_id,aa.flagFROM TEST_TB01 aaWHERE EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id) AND NOT EXISTS (SELECT 1 FROM TEST_TB03 cc WHERE aa.sensor_id = cc.sensor_id);

Execution results ：

3、 ... and 、 stay DELETE Use in statement EXISTS

stay DELETE Of SQL Use in statement EXISTS and NOT EXISTS.

stay TEST_TB01 insert data ：

INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2101,8811,' Xiamen ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2102,8812,' quanzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2103,8813,' fuzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2104,8814,' zhangzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2105,8815,' Hangzhou ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2106,8816,' Shanghai ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2107,8817,' Beijing ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2108,8818,' Shenzhen ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2109,8819,' China ');

stay TEST_TB02 insert data ：

INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2101,8811,' Xiamen ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2102,8812,' quanzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2103,8813,' fuzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2104,8814,' zhangzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2109,8819,' China ');1. stay MySQL Use in

demand ： from TEST_TB01 Delete in TEST_TB02 Records that exist in , The association condition is the of two tables sensor_id equal .

Be careful ： This example USES MySQL edition ：MySQL 5.7.33.

SQL sentence ：

DELETE FROM TEST_TB01 aaWHERE EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id);

Execution results ：

  Conclusion ： stay MySQL It is not supported in DELETE Of SQL Use in statement EXISTS and NOT EXISTS This syntax .（ This example version ：MySQL 5.7.33）.

Address this need ：

SQL sentence ：

DELETE aaFROM TEST_TB01 aa INNER JOIN TEST_TB02 bb ON aa.sensor_id = bb.sensor_id;

Be careful ： stay SQL in DELETE Followed by the alias of the table name to be deleted in the requirement .

If the alias is not used, an error will be reported ：

 2. stay Oracle Use in

demand ： from TEST_TB01 Delete in TEST_TB02 Records that exist in , The association condition is the of two tables sensor_id equal .

SQL sentence ：

DELETE FROM TEST_TB01 aaWHERE EXISTS (SELECT 1 FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id);

Execution results ：

Before execution TEST_TB01：

  Before execution TEST_TB02：

  After execution TEST_TB01：

Four 、 stay UPDATE Use in statement EXISTS

stay UPDATE Of SQL Use in statement EXISTS.

stay TEST_TB01 insert data ：

INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2101,8811,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2102,8812,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2103,8813,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2104,8814,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2105,8815,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2106,8816,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2107,8817,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2108,8818,' City ');INSERT INTO TEST_TB01 (sensor_id,part_id,flag) VALUES(2109,8819,' City ');

stay TEST_TB02 insert data ：

INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2101,8811,' Xiamen ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2102,8812,' quanzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2103,8813,' fuzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2104,8814,' zhangzhou ');INSERT INTO TEST_TB02 (sensor_id,part_id,flag) VALUES(2109,8819,' China ');1. stay MySQL Use in

demand ： stay TEST_TB01 In the update , stay TEST_TB02 Records that exist in , The association condition is the of two tables sensor_id equal .

Be careful ： This example USES MySQL edition ：MySQL 5.7.33.

SQL sentence ：

UPDATE TEST_TB01 aa SET (aa.part_id, aa.flag) = (SELECT bb.part_id, bb.flag FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id) WHERE EXISTS (SELECT 1 FROM TEST_TB02 cc WHERE aa.sensor_id = cc.sensor_id);

Execution results ：

  Conclusion ： stay MySQL It is not supported in UPDATE Of SQL Use in statement EXISTS and NOT EXISTS This syntax .（ This example version ：MySQL 5.7.33）.

Address this need ：

SQL sentence ：

UPDATE TEST_TB01 aa ,TEST_TB02 bbSET aa.part_id=bb.part_id, aa.flag=bb.flagWHERE aa.sensor_id = bb.sensor_id;

Execution results ：

Before execution TEST_TB01：

  Before execution TEST_TB02：

  After execution TEST_TB01：

 2. stay Oracle Use in

demand ： stay TEST_TB01 In the update , stay TEST_TB02 Records that exist in , The association condition is the of two tables sensor_id equal .

SQL sentence ：

UPDATE TEST_TB01 aa SET (aa.part_id, aa.flag) = (SELECT bb.part_id, bb.flag FROM TEST_TB02 bb WHERE aa.sensor_id = bb.sensor_id) WHERE EXISTS (SELECT 1 FROM TEST_TB02 cc WHERE aa.sensor_id = cc.sensor_id);

Execution results ：

Before execution TEST_TB01：

  Before execution TEST_TB02：

  After execution TEST_TB01：

  above , thank .

summary

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