In the three fields of the same table, looking for the same line, and display in the new table,

CodePudding user response:

Is this your dynamic comparison or fields are fixed?

CodePudding user response:

And this is to use a SQL statement to deal with or in a programming language to deal with"

CodePudding user response:

A, select tab1, tab2. A, tab3) from a tab1, tab2, tab3 where tab1. A=tab2. And tab2. "a=tab3. A

CodePudding user response:

As shown in the above, ID=8 rows changed
Execute the following command
The SELECT SYS (2017) ch1, * FROM teachers INTO CURSOR tmp1
The SELECT SYS (2017) ch1, 2 * FROM teachers INTO CURSOR tmp2

Can be found that peers with the same ch1 fields, then filtered
SELECT * FROM tmp1 WHERE ch1 NOT in (SELECT ch1 FROM tmp2)

CodePudding user response:

Garfield reference 4 floor VFP response:

As shown in the above, ID=8 rows changed
Execute the following command
The SELECT SYS (2017) ch1, * FROM teachers INTO CURSOR tmp1
The SELECT SYS (2017) ch1, 2 * FROM teachers INTO CURSOR tmp2

Can be found that peers with the same ch1 fields, then filtered
SELECT * FROM tmp1 WHERE ch1 NOT in (SELECT ch1 FROM tmp2)

If there is no this example, I don't know what this sys (2017)?