Shulou(Shulou.com)06/01 Report--

Copy table structure and table data:

Create table table_name_new as select * from table_name_old

Copy the table structure:

Create table table_name_new like table_name_old

Copy table data:

Insert into K20_JDBC_TMP select * from K20_JDBC

Set to empty field data to-1:

Update K20_JDBC_TMP set JDBCTIME_MS=-1 WHERE JDBCTIME_MS is NULL

Clear the table data:

Truncate table K20_JDBC_TMP

Rename the table name:

ALTER TABLE old_name RENAME TO new_name

Or

Rename table to table_new

Syntax for adding fields:

Alter table tablename add (column datatype [default value] [null/not null], … .)

Alter table K20_JDBC_TMP2 add T1 CHAR (20) default null; / / is empty by default

Modify the syntax of the field:

Alter table tablename modify (column datatype [default value] [null/not null], … .)

Alter table K20_JDBC_TMP2 modify T1 CHAR (30) default null

Syntax for deleting a field:

Alter table tablename drop (column)

Alter table K20_JDBC_TMP2 drop column T1

Compare the data differences between the two tables:

Select * from B minus select * from A

Selecet pno,cno from A minus select pno,cno from B

Compare two tables with the same structure and insert different data into the third table.

Insert into K20_JDBC_TMP2 (TMZDIFF,WRITETIME,NODE,TIMESTAMP,IP,NODENAME,SERVERNAME,PROVIDERNAME,JDBCNAME,CREATECOUNT,CLOSECOUNT,POOLSIZE,FREEPOOLSIZE,USEDMAX_PCT,JDBCTIME,WAITTIME,USETIME,WAITINGTHREADCOUNT,JDBCTIME_MS,WAITTIME_MS,USETIME_MS) select * from K20_JDBC MINUS SELECT * FROM K20_JDBC_TMP

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.