How to replace rows and columns using SQL statements, as shown in question 30

select , from

select , from test123 t1 where = 'my work') a

inner join(

select , from test123 t2 where = 'our work' ) b

on =inner join(

select , from test123 t3 where = 'his work' ) c

on = This is your answer.

Your columns are not fixed, you can only use dynamic sql, use cursors.

Write a process, and you're done.

update table set mc=mc1+'$'+mc2+'$'+mc3+'$';

Then execute. update table set mc = substring(mc,2,length(mc)-1) where mc like'$%';

The latter sentence can be executed at most 2 times, that is, if you are afraid that mc1 and mc2 are empty, you can directly fill in $.

Columns with no data are null (null) and written like this.

select mc=isnull(mc1+'$','')+isnull(mc2+'$','')+isnull(mc3+'$','') from tablename

Otherwise, it should be so.

select mc=case when mc1>'' then mc1+'$' else '' end,case when mc2>'' then mc2+'$' else '' end,case when mc3>'' then mc3+'$' else '' end

from tablename

Your question is vague.

Let's say your table looks like this: Data Table Name (Payroll).

Number, Name, Salary, Bonus.

1 card three 100 50

2 Lee 4 150 60

3 Kings 5 90-40

4 Zhao 6 200 70

If you want to replace Li Si's salary with your variable value.

Define the data source gcn

dim bianliang 'Your variables.

dim rs as

set rs=g_"update pay table set salary='" & bianliang & "'where name='Li Si'")

If you want to replace the variable with Li Si's salary, this is it:

dim bianliang 'Your variables.

dim rs as

set rs=g_"select Salary from Payroll where name='Li Si'")

bianliang=

decalre @a int

select @2=id (the column name of the table).

from the table name.

where condition.

Note: Depending on the condition, there should be one value, and multiple worth words replace the result of the last query.

update table name.

set column name = the value you want to replace (in quotation marks if it's a string) (or column name =: your variable).

where sets the condition (that is, the condition is met to be a good man).

Let's assume that the first column in Table 1 is the serial number, the second column is the code, and the first column in Table 2 is the serial number, the second column is the code, and the third column is the name

update Table 1

set Table 1Code = Table 2Name.

where Table 1Code = Table 2Code name.

Regardless of the ranks

Assume that Table 1 is table1 and the fields are id and cid.

Table 2 is table2 and the fields are id, cid, and cname.

then update table1 set = where =

update Table 1 Set ABCD field = (select name from Table 2 where table field = table field).

update set a.Letter column = bChinese character column from Table 1 a, Table 2 b where aLetter column = bLetter columns.

select * from arctype case when topid=0 then topid else reid end;

Don't know what database you are, I'm writing sqlserver

It's a trifle. update your table set Columns to replace =replace (Columns to replace,'dedecms','t775

where article id between 1 and 200

If you have any problems in the future, I will try to solve them for you as quickly as possible.

If your keyword is in a field, that's fine.

update table set field name ='t775'where id<=200 and fieldname='dedecms'