Solve the problem that Oracle cannot use more than 1000 in statements

stay oracle in , Use in Method when querying records , If in The number of subsequent parameters exceeds 1000 individual , Then there will be mistakes ,JDBC Will throw out “java.sql.SQLException: ORA-01795: The maximum number of expressions in the list is 1000” This anomaly .

Here's my solution ：

One 、 Create temporary tables

ORACLE There are two types of temporary tables ： Session level temporary tables and transaction level temporary tables .

1、ON COMMIT DELETE ROWS

It is the default parameter of the temporary table , Indicates that the data in the temporary table is only in the process of transaction （Transaction） Effective in , When a transaction commits （COMMIT） after , The temporary segment of the temporary table will be automatically truncated （TRUNCATE）, But the structure of the temporary table And metadata is also stored in the user's data dictionary . If the temporary table completes its mission , It's best to delete the temporary table , Otherwise, the database will leave a lot of table structure and metadata of temporary tables .

2、ON COMMIT PRESERVE ROWS

It means that the contents of the temporary table can exist across transactions , however , When the session ends , The temporary segment of the temporary table will be discarded with the end of the session , The data in the temporary table is naturally discarded . But the structure and metadata of the temporary table are also stored in the user's data dictionary . If the temporary table completes its mission , It's best to delete the temporary table , Otherwise, the database will leave a lot of table structure and metadata of temporary tables .

create global temporary table test_table 
(id varchar2(50), name varchar2(10)) 
on commit preserve rows; -- Create a temporary table （ Current session effective ）

-- Add data 
insert into test_table VALUES('ID001', 'xgg');
insert into test_table VALUES('ID002', 'xgg2');

select * from test_table; -- Query data 

TRUNCATE TABLE test_table; -- Empty temporary table data 
DROP TABLE test_table; -- Delete temporary table 

After creating the temporary table ,in Sub query can be used in the statement , So there won't be more than 1000 Wrong report

select * from table_name where id in(select id from test_table);

Two 、 Use in() or in()

The official said ： A comma-delimited list of expressions can contain no more than 1000 expressions. A comma-delimited list of sets of expressions can contain any number of sets, but each set can contain no more than 1000 expressions

Use here oracle tuple（ A comma-delimited list of sets of expressions） That is, tuples , The grammar is as follows ：

SELECT * FROM TABLE_NAME WHERE (1, COLUMN_NAME) IN 
((1, VALUE_1), 
(1, VALUE_2), 
...
...
...
...
(1, VALUE_1000),
(1, VALUE_1001));

For example, we want to go through users from the user list id Query user information can be written as follows ：

select * from user u where (1, u.id) in ((1, 'id001'),(1,'id002'),(1,'id003'))

The above statement is actually equivalent to ：

select * from user u where (1=1 and u.id='id001') or (1=1 and u.id='id002') or (1=1 and u.id='id003')

Most of your projects will use ORM The frame is like MyBatis We can use MyBatis Of foreach It was written here :

where u.id in
<foreach collection="userIds" item="item" separator="," open="(" close=")" index="">
	#{item}
</foreach>

Now change to ：

where (1, u.id) in
<foreach collection="userIds" item="item" separator="," open="(" close=")" index="">
	(1, #{item})
</foreach>

3、 ... and 、 summary

If it helps you , Please point a favor or collect it ！ Your attention is my biggest motivation .