Using SQL statements to merge two unrelated tables?

You can simply use the SQL statement query result merging method. select * from a union all select * from b union all select * from c

Select * from aunion allselect * from bunion allselect * from c c table is your new blank table, which is similar to the previous question.

1. The first is to use a temporary table to put all the data in one table.

insert into qunlist select * from qunlist89,90,91,92;

Then query in the qunlist.

2. The second way is to use the union all way to query.

select * from qunlist89union all

select * from qunlist90;

1. First, open the SQL Server management tool and use the SELECT statement to query the records of the current table.

2. Next, you need to sort the table by row number, and save the sorted table to the temporary table.

3. Next, write the update statement, here we use table association, as shown in the following figure, the sorting field of the temporary table is reassigned to the sorting field of the table through association.

4. Then remember to delete the temporary table at the end, as shown in the figure below, if you don't delete the temporary table, an error will be reported next time.

5. After executing the SQL statement, you will find that the value of the px field in the record has not changed, as shown in the following figure, which is due to the problem of sorting method.

6. Next, sort in the row number by the descending order of the px field, as shown in the following figure, after the execution, you will find that the value of the px field has changed, that is, the sql merge shows that the two tables without association are successful.

Preferably, you should merge the data in Table 1, Table 2, and Table 3 into a table and use Union All to merge them together. Ignore whether the names are duplicated or not.

However, when performing the merger, it is necessary to put a label on each data to be merged, representing the data from which table this is, and this label is finally used to distinguish the different scores of the same person.

The merged data is converted from row to column.

select a.Entrant's name, bLong-distance running score, cSwimming score, dHigh Jump Score from (

select Participant Name from (.

Select Participant's Name from Table 1

UnionSelect Participant Name from Table 2 UnionSelect Participant Name from Table 3) as t) as a

Left join Table 1 as b

on a.Entrant's name, bEntrant's name.

Left join Table 2 as c

on a.Participant's name = cEntrant's name.

Left join Table 3 as d

on a.Participant's name = dEntrant's name.

If it's a vertical merge, use Union All

There are two tables A and B that are added

The table structure has two fields: date1 and a2

Table b has a field date1

select date1,a2 from (select date1,a2 from a

union all

select date1,null from b)order by date1;

Note that the number of fields in the two tables in union all must be the same, and the missing fields must be filled with null.

Sorting must be done outside of the subquery.

where [fields in table a] = [fields in table b].If you can't meet this condition, it is recommended that you reconstruct the logical structure of the data.

In the case of where, you can set the sorting with the sorting condition. order by + ascending or descending.

Use union or union all

For example, select * from a union, all select * from b, and then nest a layer of queries to sort the time order by