Database Lib7 2nd, 3 questions (creating indexes and triggers)

2. Establish an appropriate index for the tables created above, and describe the process of indexing (can or write SQL). It is required to establish an index on the Sno, PNo fields in the SPJ, and an index for the combination of (PNo, Jno). is the index on SNO and pno a clustered index or a nonclustered index? Why?

Attached code:

1 Create Index  on SPJ (SNo) 2 Create Index  on SPJ (PNo) 3 Create Clustered Index  on SPJ (SNo, PNo);

3. Please teach yourself the trigger section of the Chinese book P160, and with the help of SQL Server, create a trigger that, when inserting data into table p,

Insert this data into a new table of your own, and the structure of the table is consistent with the P-label (append).

Attached code:

1 Create TriggerInsert_trigger2      onBranch3      for Insert4  as 5     Print 'Data Backup ...'6     if(object_id('Bankup','U') is  not NULL)7         Insert  intoBankupSelect *  fromBranch;8     Else 9         Select *  intoBankup fromBranch;Ten     Print 'Data Backup Complete' One Go