Frog Frog recommended: Organize some SQL database skills, paste

Frog Frog recommended: Organize some SQL database skills, paste
How to delete a column in a table that repeats, for example
Table [table1]
ID Name
1 AA
2 BB
3 cc
1 AA
2 BB
3 cc
I think the last watch is like this.
ID Name
1 AA
2 BB
3 cc
Reply:
Save the record in a temporary table #t, save a duplicate record, and then save the record in the temporary table #t back into the original table, noting that "SELECT DISTINCT Id,class,name" contains all the fields you need, otherwise some fields are deleted.
Execute the following code in the query manager:
-----------------------------
SELECT DISTINCT ID,, name
Into #t
From table1 DELETE table1
INSERT
into table1
SELECT *
From #t
------------------------------
Two. Find people who will both VB and PHP
The table is like this:
ID Employee Skills
1 1 VB
2 1 PHP
3 1 ASP
4 2 PHP
5 3 ASP
6 4 VB
7 4 ASP
From this table to find both VB and PHP, how to write SQL?
Reply:
---------------------------------------------------------------------------------------------
Select employee from [table] where employee in (select employee from [table] where skill = ' VB ') and skill = ' PHP '
----------------------------------------------------------------------------------------------
Three. Database Consolidation issues
Two tables in Access that want to merge the contents of two tables
The table [a] structure is as follows:
[ID] Number autonumber
[Name] Name text
[Prices] Price number
[Guige] Specification text
[Changjia] Manufacturer's text
[Baozhuang] Wrapping text
[Danwei] Unit text
A total of 900 records, except the ID and Name fields, all other can be empty
The table [b] structure is as follows:
[ID] Number autonumber
[Name] Name text
[Prices] Price number
[Changjia] Manufacturer's text
[Danwei] Unit text
[Xingzhi] nature of the text
A total of 800 records, in addition to the ID and name fields, less than table [a] a few fields, but also more than one [Xingzhi] of the word Fuan other can be empty
Now you want to generate a new table [C], which is structured as follows, and content is the sum of the contents of two tables,