I am trying to migrated MySQL 5.0 views to Oracle 12c. This is the syntax I have in MySQL:
select count(`table1`.`uuid`) AS `Count`,
`table2`.`description` AS `STATUS`,
`table3`.`name` AS `Court`
from ((`table2` join `table1`)
join `table3`)
where ((`table1`.`statusCode` = `table2`.`code`)
and (`table3`.`uuid` = `table1`.`courtUuid`))
group by `table1`.`courtUuid`,`table2`.`description`;
This is the syntax I have for Oracle 12c:
select count(table1.uuid) AS Count,
table2.description AS STATUS,
table3.NAME as Court
from table2
join table1
on (table1.statuscode = table2.code)
join table3
on (table3.uuid = table1.courtuuid)
group by table1.courtuuid,table2.description;
When I run the Oracle 12c syntax, I get:
ORA-00979: not a GROUP BY expression
00979. 00000 - "not a GROUP BY expression"
*Cause:
*Action:
Error at Line: 3 Column: 1
However, if I add table3.NAME as part of the group by, I get 866 rows. The query in MySQL produces 1025 rows.
select count(table1.uuid) AS Count,
table2.description AS STATUS,
table3.NAME as Court
from table2
join table1
on (table1.statuscode = table2.code)
join table3
on (table3.uuid = table1.courtuuid)
group by table1.courtuuid,table2.description,table3.NAME;
Can someone help me figure this one out?
You probably want:
select count(table1.uuid) AS Count,
table2.description AS STATUS,
table3.NAME as Court
from table2 join
table1
on table1.statuscode = table2.code join
table3
on (able3.uuid = table1.courtuuid
group by table3.name, table2.description;
The unaggregated columns in the select should be in the group by. Unfortunately, MySQL has a (mis)feature that does not require this logic.
Strictly speaking, you could also do:
select count(table1.uuid) AS Count,
table2.description AS STATUS,
max(table3.NAME) as Court
from table2 join
table1
on table1.statuscode = table2.code join
table3
on table3.uuid = table1.courtuuid
group by table1.courtuuid, table2.description;
This is more equivalent to your query, but the first version is probably what you intend.
Related
I'm trying to convert this MySQL query to SQL Server, but I do not know much about SQL Server
SELECT
*
FROM
Table1 AS T1
INNER JOIN Table2 AS T2
ON T1.Column1 = T2.ColumnX
WHERE
T1.ColumnY = 'xxxx'
GROUP BY
T1.Column1
Somebody can help me?
Your query is just an erroneous query, because you are using select * with group by. This query uses a MySQL extension. And, the default settings in more recent versions of MySQL would generate an error.
Here is one method for converting this to SQL Server:
SELECT TOP (1) WITH TIES *
FROM Table1 AS T1 INNER JOIN
Table2 AS T2
ON T1.Column1 = T2.ColumnX
WHERE T1.ColumnY = 'xxxx'
ORDER BY ROW_NUMBER() OVER (PARTITION BY T1.Column1 ORDER BY (SELECT NULL)) ;
Probably a better method (from a performance perspective) uses a lateral join:
SELECT *
FROM Table1 T1 CROSS APPLY
(SELECT TOP (1) T2.*
FROM Table2 T2
WHERE T1.Column1 = T2.ColumnX
) T2
WHERE T1.ColumnY = 'xxxx' ;
Both of these choose arbitrary rows from Table2 when there is more than one match.
I am trying to use join to connect multiple tables in MS Access to get count values. But I don;t know it gives wrong count values. If I try to join them individually, then it gives me correct count values.
I have 3 Tables. Table 2 and Table 3 are independent and are connected to Table 1. Test 2 and test 3 are basically text values and I want to count the rows .
Table1(ID1(Primary Key),Name)
Table2(ID2(Primary Key), ID1(Foreign Key), Test2)
Table3 (ID3(Orimary Key), ID1(Foreign Key), Test3)
The Query that I get from MS Access is given below:
SELECT Table1. ID1, Count(Table2.Test2) AS CountOfTest2, Count(Table3.Test3) AS CountOfTest3
FROM (Table1 INNER JOIN Table2 ON Table1.ID1 = Table2.ID2)
INNER JOIN Table3 ON Table1. ID1 = Table3.ID3
GROUP BY Table1.ID1;
But this gives me wrong Count Values.
Can someone please help me.
Thanks.
When I use it individually, it gives me correct count value:
SELECT Table1. ID1, Count(Table2.Test2) AS CountOfTest2
FROM Table1 INNER JOIN Table2 ON Table1.ID1 = Table2.ID1
GROUP BY Table1.ID1;
SELECT Table1. ID1, Count(Table3.Test3) AS CountOfTest3
FROM Table1 INNER JOIN Table3 ON Table1.ID1 = Table3.ID1
GROUP BY Table1.ID1;
But when I try to join Table1, Table2 and Table 3 in MS Acces, it gives me incorrect count values.
SELECT Table1. ID1, Count(Table2.Test2) AS CountOfTest2, Count(Table3.Test3) AS CountOfTest3 FROM (Table1 INNER JOIN Table2 ON Table1.ID1 = Table2.ID1) INNER JOIN Table3 ON Table1. ID1 = Table3.ID1 GROUP BY Table1.ID1
As per my understanding it is taking the count value of 1st query in the parenthesis and multiplying it with the count values of the other inner join.
I have tried many things but don't know what to do. Access adds parenthesis for some reason.
If I can assume test2 and test 3 are unique to each record (perhaps it would be better to count the PK?)
SELECT Table1.ID1
, Count(distinct Table2.Test2) AS CountOfTest2
, Count(distinct Table3.Test3) AS CountOfTest3
FROM Table1
INNER JOIN Table2
ON Table1.ID1 = Table2.ID2
INNER JOIN Table3
ON Table1.ID1 = Table3.ID3
GROUP BY Table1.ID1;
Or you may have to get the counts before the joins though the use of inline views. You could use window functions if MSSQL SERVER but Access needs the inline views.
SELECT A.ID1
, B.CountOfTest2
, C.CountOfTest3
FROM Table1 A
INNER JOIN (SELECT Table2.ID2, count(table2.test) as CountOfTest2
FROM Table2
GROUP BY Table2.id) B
ON Table1.ID1 = B.ID2
INNER JOIN (SELECT Table3.id, count(table3.test3) as CountOfTest3
FROM Table3
GROUP BY Table3.id) C
ON B.ID1 = C.ID3
GROUP BY A.ID1;
Yup i had the same problem when i was trying to do this. just use the double sql function to counteract the html and you should be good. once the query has been doubled it will react like a C++ quota statement. If this fails you can always just quantify the source fields to adhear to the table restrictions. its actually a piece of cake i hope this helped.
I am trying to get results where CountId equals zero. I tired the code below but does not work.Can someone please please help :)
SELECT table1.id,table1.name2,table1.name3,table1.name4,table1.name, COUNT(table2.id ) AS CountId
from table1
LEFT JOIN table2
ON table1.name4 = table2.name4
AND table1.name3 = table2.name3
AND table1.name2 = table2.name2
WHERE CountId = 0
You cannot use an aggregate function (such as SUM,COUNT,etc) in WHERE clause.
Use HAVING clause after GROUP BY. Also it is a good practice to use alias names when you join multiple tables.
SELECT t1.id,t1.name2,t1.name3,t1.name4,t1.name, COUNT(t2.id) AS CountId
from table1 t1
LEFT JOIN table2 t2 ON t1.name4 = t2.name4
AND t1.name3 = t2.name3
AND t1.name2 = t2.name2
GROUP BY t1.id,t1.name2,t1.name3,t1.name4,t1.name
HAVING COUNT(t2.id) = 0
Here is my code:
SELECT field1, field2,
(SELECT * FROM table1 WHERE a = field2),
(SELECT COUNT(*)
FROM (SELECT *
FROM table2
WHERE c = field2) as t1) as count
FROM table3;
...and here is error message:
/* SQL Error (1054): Unknown column
'field2' in 'where clause' */
I want to execute one query, to get table2's total counts.
The problem is that you're trying to use a variable declared in the outer query in the inner query. Variables are scoped the opposite way in SQL, you only have access to inner queries. What you want to do (I believe) is look for the number of table2 that have a c that matches the a from table1. This should give you that answer.
SELECT
table1.a,
table2.c,
count(*)
FROM
table1
JOIN
table2 ON table2.c = table1.a
GROUP BY
table1.a
I re-wrote your query as:
SELECT t3.field1,
t3.field2,
t1.*,
t2.cnt
FROM TABLE3 t3
LEFT JOIN TABLE1 t1 ON t1.a = t3.field2
LEFT JOIN (SELECT t.c,
COUNT(*) AS cnt
FROM TABLE2 t
GROUP BY t.c) t2 ON t2.c = t3.field2
The 1054 error is due to referencing field2 two subqueries deep - most only support one level deep.
UPDATE:
I want to edit the answer, since in MySQL 8.0 your query is already correct, derived tables can access external references no matter the level.
SELECT field1, field2,
(SELECT 'hola' FROM table1 WHERE a = field2),
(SELECT COUNT(*)
FROM (SELECT *
FROM table2
WHERE c = field2) as t1) as count
FROM table3;
"Prior to MySQL 8.0.14, a derived table cannot contain outer references. This is a MySQL restriction that is lifted in MySQL 8.0.14, not a restriction of the SQL standard. For example, the derived table dt in the following query contains a reference t1.b to the table t1 in the outer query:" https://dev.mysql.com/doc/refman/8.0/en/derived-tables.html
I'm trying a subquery in MySQL using max(), and I keep running into an error. The gist of the query is below (though I've changed the field names).
select table1.field1, table1.field2, table2.field3, table2.field4, table3.field5,
(select max(age)
from age_table
where age_table.person = table2.person)
from table1
inner join table2 on table2.person = table1.person
inner join table3 on table3.person = table1.person
inner join age_table on age_table.person = table1.person
When I try this, I get a syntax error that points to
'from age_table where age_table.person=table2.person'
...but I can't figure out what the problem is.
Use table aliases to differentiate between tables, without having to use the full table name:
SELECT t1.field1, t1.field2, t2.field3, t2.field4, t3.field5,
(SELECT MAX(at.age)
FROM AGE_TABLE at
WHERE at.person = t2.person) AS max_age
FROM TABLE1 t1
JOIN TABLE2 t2 ON t2.person = t1.person
JOIN TABLE3 t3 ON t3.person = t1.person
I removed what appeared to be a redundant JOIN to the AGE_TABLE, seeing as it wasn't used in the SELECT clause.
It's also good habit to define a column alias for derived column values - makes them easier to reference. See "max_age" for an example.
You need to create an alias for your subquery eg:
(select max(age) from age_table where age_table.person = table2.person) temp
and leave rest of the things as they are.