Table 1: id#, name, color
Table 2: id#
I would like to get all the results from Table 1 WHERE color = "green". After finding the subset of color 'green' from table 1, I then want to find all the matching id#'s from Table 2.
Essentially getting the set from Table 1 with a color=green that exist in Table 2.
Thanks for help with this query!
SELECT * FROM TABLE2
WHERE ID IN (SELECT ID FROM TABLE1 WHERE color = 'green');
Is this what you want?
SELECT *
FROM Table1 t1
JOIN Table2 t2 ON t1.Table2_ID = t2.ID
WHERE t1.Colour = 'Green'
Edit: Just noticed you've updated the question with the column names. I'll let you do the substitution ;)
Related
Consider the below table T1
FLOOR...ANIMAL...COLOUR
1...Cat...Black
1...Dog...Black
1...Cat...White
2...Dog...White
2...Dog...Brown
3...Cow...Brown
3...Dog...White
3...Cat...Black
Now, I with query: Select * from T1 where animal='cat'; got this Table T2
Table T2
FLOOR...ANIMAL...COLOUR
1...Cat...Black
1...Cat...White
3...Cat...Black
The result I want is: All the elements present in Table T2 and only(FLOOR,ANIMAL) of Table T1. Something like the below Table T3:
Table T3
FLOOR...ANIMAL...COLOUR
1...Cat...Black
1...Cat...White
3...Cat...Black
1...Dog
2...Dog
2...Dog
3...Cow
3...Dog
How this Table T3 can be acheived? Any suggestions?
Thanks in advance.
You could try taking the UNION of two TABLES wherein the second TABLE should have its third column as empty string:
select * from T1 where animal = 'cat'
UNION
select floor, animal, " " as color from T1 where animal <> 'cat';
You can try with case
like this :
case when ANIMAL = "cat" then COLOUR else '' end
I have 2 tables. I want to find out whether the values present in the first table is there in another table with a different field name.
Here is how it looks,
Table1
BillNo
43529179
43256787
35425676
25467778
24354758
45754748
Table2
BNo
113104808
25426577
268579679
2542135464
252525232
235263663
I have 137 records in table1 that needs to be checked against table2.
Instead of doing it one by one using the following command,
Select * from Table2 where BNo = '43529179';
This gives the result for just the mentioned value. Is there a way to check for all the values in a single query?
Thanks!
You can use a sub-select to compare against:
Select * from Table2 where BNo IN (SELECT BillNo FROM Table1);
That will "evalaute" to something like Select * from Table2 where BNo IN (113104808, 25426577, 268579679, 2542135464, 252525232, ...);
Join the tables, and check how many matching records there are:
select
count(*) as Matches
from
Table1 as t1
inner join Table2 as t2 on t2.BNo = t1.BillNo
You can also use a left join to pick out the records in table 1 that has no matching record in table 2:
select
t1.BillNo
from
Table1 as t1
left join Table2 as t2 on t2.BNo = t1.BillNo
where
t2.BNo is null
I have 2 tables in MySQL, the first one has 2 columns: ID and name, the second has 3 columns: firstTableId (foreign key on the first table), key, value.
I have the following rows in table 1:
1,Bob
2,Alice
3,Fred
I have the following rows in table 2:
1,age,20
1,gender,male
2,age,20
2,gender,female
3,age,18
3,gender,male
I would like to write a select query using only the last 2 columns on the second table (key and value) that returns only Bob form the first table, but I can't seem to figure it out.
Essentially I want to select from the first table all rows where, in the second table, we have key=age and value=20 for one row, and key=gender and value=male in another row. Can anyone point me in the right direction ? Manipulating table structure is not preferred as this is a simplified example and both "key" and "value" columns in the second table can be pretty much anything, it's not actually limited to "age" and "gender".
Thanks in advance.
You can do this with a self join like this:
select
*
from
table1 t1
inner join table2 age on t1.id = age.id
inner join table2 gender on t1.id = gender.id
where
(age.`key` = 'age' and age.value = 20)
and
(gender.`key` = 'gender' and gender.value = 'male')
An additional tactic you may want to try is a PIVOT query. Mysql doesnt have anything native to support pivot's, but there are several examples of how to do them.
You can see it working in this fiddle
Use two IN clauses (or two EXISTS clauses).
select *
from table1
where id in (select firstTableId from table2 where key = 'age' and value = '20')
and id in (select firstTableId from table2 where key = 'gender' and value = 'male');
With EXISTS:
select *
from table1
where exists (select * from table2 where key = 'age' and value = '20' and firstTableId = table1.firstTableId)
and exists (select * from table2 where key = 'gender' and value = 'male' and firstTableId = table1.firstTableId);
i have a db like this:
Table1:
id
id_item
table (enum: 'table2','table3','table4')
table2:
id
value
table3:
id
value
table4:
[...]
And i want to run a query like this:
SELECT t1.id, t2.value FROM table1 AS t1
LEFT JOIN table1.table as t2 ON t1.id_item=t2.id
Is it possible? or i have to select first table1 and after the value?
( sorry for my bad eng :) )
If I understood the last column in Table 1 correctly and it is just a string, you can't.
You cannot write a column into the FORM-clausal and wait for mysql to evaluate it for every row and find the correct table to join it with.
To do this you will need to create a view where you will have the data from all the tables, together with the table name as an additional column. Afterwards you can perform a join like that between Table1 and the new view
I'm desperate with this query. I have two tables table1 and table2, tables are identical but they have different data. I'm trying to remove duplicities by columns code and manufacturer. To do that I need in final result ID from table1 ID from table2 and also columns code and manufacturer
SELECT * FROM (
SELECT id,code,manufacturer FROM table1 WHERE manufacturer = 1
UNION SELECT id,code,manufacturer FROM table2 WHERE manufacturer = 1
) AS t GROUP BY code HAVING COUNT(*) > 1
But in result i got only values from table1. It's OK but I just need to get there id from table2 too. Please can anyone give me some tips how to do this ?
You have two basic problems:
Problem 1:
You are using UNION when you should be using UNION ALL, because UNION removes duplicates!
Problem 2:
This isn't the right way to go about the problem. You should be using a simple join, not a union.
Try this:
SELECT
t1.id as table1_id,
t2.id as table2_id,
t1.code,
t1.manufacturer
FROM table1 t1
JOIN table2 t2
ON t2.code = t1.code
AND t2.manufacturer = t1.manufacturer
WHERE manufacturer = 1 -- this WHERE clause is optional
Your use of the WHERE clause is a little odd - consider removing it to get all duplicates from all manufacturers.