SQL advanced statement Query

For example:

1. Connection Method

Select a. *, B. * From t2_mz_sfdj a join t2_mz_sfdjmx B on A. Djid = B. Djid where a. ssje> 5000

2. Use a connection to modify table records

Update a set a. ZY = B. ZY from t2_mz_sfdj a inner join t2_mz_sfmx B join a. Djid = B. Djid where a. State = 'account'

3. Delete with connection

Delete from t2_mz_sfdj a join t2_mz_sfmx B on A. Djid = B. Djid where State = 'drafts'

4. Use in to select

Select * From t3_spk where spid not in (select * From t1_spjk) can select records not in t1_spjk.

5. compress the database with statements (logs can be compressed to 1 MB)

Backup log databsename with no_log; DBCC shrinkdatabase (databasename, 0)