I have a table A that is a singular column called "Column_Name" and its values are a list of names. I have another table B whose columns are those values of "Column_Name" in table A. For example the values of "Column_Name" in table A are (Date, Age, Location). Then in table B, its actual columns are (Date, Age, Location) and those columns have their own respective values. I am trying to select the columns from table B that are values in "Column_Name" in table A. Is there a way to do this? I think I can use the IN operator in a WHERE clause, but not exactly sure how.
I don't know if I got it correctly,
Considering that the column_name in tableA is separated by commas,
would it be something like this?
select * from tableB
where Dt in (select SUBSTRING_INDEX(Column_Name,',',1) from tableA)
or Age in (select SUBSTRING_INDEX(Column_Name,',',2) from tableA)
or Location in (select SUBSTRING_INDEX(Column_Name,',',3) from tableA);
here is the example
https://www.db-fiddle.com/f/pUytYwKpK4mRsk76oFonV8/0
Related
I'm trying to create a table from multiple tables.
table a has list of IDs and I need count of IDs stored in table C.
Table b has list of IDs and need the count of them as well in table C.
I'm trying below but getting an error:
Create or replace tablec as
select
Count(id) as total
from table a,
select count(ref) as ref_total
from table b
My desired output should look like below and should be filter applied by date.
Consider using a subquery for each count like below.
CREATE OR REPLACE TABLE TableC AS
SELECT (SELECT COUNT(id) FROM TableA) AS total,
(SELECT COUNT(ref) FROM TableB) AS ref_total
;
output:
But date range is something optional. For date range, I'm thinking to get whole data in new table then I can run select on table C
I think you can add date filter in WHERE clause of each subquery for your purpose.
CREATE TABLE student_activestudent AS
(
SELECT *
FROM
student
INNER JOIN
activestudent ON activestudent.studentnumber=student.studentnumber
);
I am expecting a table with 2 columns of studentnumber but I received Duplicate error instead --> Duplicate column name 'studentnumber'
A database table must have unique column names.
When you do select * you will get all columns from all tables and studentnumber exists on both student table and activestudent table. So to solve you problem specify the columns you want instead of *
CREATE TABLE student_activestudent AS
(
SELECT
student.studentnumber,
..Other columns..
FROM
student
INNER JOIN
activestudent ON activestudent.studentnumber=student.studentnumber
);
At the very least, studentnumber is duplicated. In general, I strongly recommend that a view list all the columns explicitly. This protects the view if underlying columns change.
That said, if studentnumber is the only column, then you can do:
CREATE TABLE student_activestudent AS
SELECT *
FROM student s JOIN
activestudent ast
USING (studentnumber);
With using, the * does not repeat the join keys.
You cannot select two tables that have same column's name.
The best way is not to select *
Select by column and if the column is same you can put [as]
Example
SELECT student.studentnumber as stuNumber, activestudent.studentnumber as actstuNumber
I'm having an issue copying one table's data to another. I have around 100 or so individual tables that have generally the same field names but not always. I need to be able to copy and map the fields. example: source table is BROWARD and has column names broward_ID, name, dob, address (the list goes on). The temp table I want to copy it to has ID, name, dob, address etc.
I'd like to map the fields like broward_ID = ID, name = name, etc. But many of the other tables are different in column name, so I will have to write a query for each one. Once I figure out the first on, I can do the rest. Also the column in both tables are not in order either..thanks in advance for the TSQL...
With tables:
BROWARD (broward_ID, name, dob, address) /*source*/
TEMP (ID, name, address,dob) /*target*/
If you want to copy information from BROWARD to TEMP then:
INSERT INTO TEMP SELECT broward_ID,NAME,ADDRESS,DOB FROM BROWARD --check that the order of columns in select represents the order in the target table
If you want only copy values of broward_ID and name then:
INSERT INTO TEMP(ID, name) SELECT broward_ID,NAME FROM BROWARD
Your question will resolve using update
Let's consider we have two different table
Table A
Id Name
1 abc
2 cde
Table B
Id Name
1
2
In above case want to insert Table A Name column data into Table B Name column
update B inner join on B.Id = A.Id set B.Name = A.Name where ...
I want to return all the rows from a table which are unique. I.e. if a certain field in two rows contain the same name, that name shouldn't be shown.
Since you want only the uniques names (and not an unique row for every names like you could have with DISTINCT), you have to use a GROUP BY and a HAVING (instead of a WHERE, because your parameter is the result of a function, not a variable) :
SELECT name FROM myTable GROUP BY name HAVING COUNT(name) = 1
SELECT DISTINCT column_name FROM table
If you want the complete rows, then use row_number() or distinct on:
select distinct on (name) t.*
from table t
order by name;
i have 2 tables.
TABLE A COLUMNS - aid , aname
TABLE B COLUMNS - bid , bname
from table A, i will pick up data from column 'aid',
AND insert it in 'bid' column of table B , but in bname column of table B, i will insert a new value. how do i do this?
create table A(aid int,aname char)
insert into A values(111, 'e')
create table B(bid int, bname char)
insert into B (bid,bname)
bid will take value from the query : select aid from a
bname will get a new value -m
expected result should be : THE TABLE B WILL HAVE :
bid bname
--- -----
111 m
Try this:
insert into b (bid, bname) select aid, 'm' as bname_fixed_val from a
Two facts enabled the solution above:
The insert .. select clause allows you to insert the values returned with any select.
You can return constant values as fields with select, like for instance:
SELECT 0 as id, 'John' as name
Combining these two points together, I used an insert..select clause to select the field value from the first table (aid), along with a constant value for the second field (m). The AS bname_fixed_val clause is simply a field alias, and can be omitted.
For more information on SQL, here 's a link: http://www8.silversand.net/techdoc/teachsql/index.htm, although googling it wouldn't hurt also.