I get the error invalid column media.user and tuid. Before running this i see that media.user does exist and i would think that the coalesce() as tuid would solve the tuid problem.
Why are these columns invalid?
CREATE TRIGGER media_comment_trig_0 ON media_comment AFTER INSERT AS
INSERT INTO user_incoming_media_comments(recipient, comment)
SELECT coalesce(p.author, [media.user]) as tuid, INSERTED.id
FROM media
JOIN INSERTED ON media.id = INSERTED.media
LEFT JOIN media_comment p on p.id=INSERTED.parent
WHERE tuid <> INSERTED.author;
USER is a reserved SQL keyword, so you'll need to write it as [media].[user] instead.
Also, you can't use an alias in the WHERE clause. You'll have to put the full expression back in there:
WHERE coalesce(p.author, [media].[user]) <> INSERTED.author;
change [media.user] to [media].[user], the [ and ] cause SQL Server to think [media.user] is the column name, and not the table.column.
Also, you need to change WHERE tuid <> INSERTED.author; to WHERE coalesce(p.author, [media].[user]) <> INSERTED.author;. You must repeat the COALESCE and can't use the column alias in the WHERE.
Does the column exist in the table? COALESCE will substitute a NULL value not a missing column.
Also this [media.user] should be media.[user]
you also need to repeat it in your WHERE clause
Related
I need help to understand what I did wrong ... I'm a beginner so excuse me the simple question!
I have two tables in which I want to do a JOIN where, in one of the columns I had to use REPLACE to remove the text 'RIxRE' that does not interest me.
In table 1, this is the original text of the column id_notification: RIxRE-1787216-BSB and this is the text that returns when using REPLACE: 1787216-BSB
In column 2, this is the text that exists: 1787216-BSB
However, I get the following error:
# 1054 - Unknown column 'a.id_not' in 'on clause'
SELECT *, REPLACE(a.id_notificacao,'RIxRE','') AS id_not
FROM robo_qualinet_cadastro_remedy a
JOIN (SELECT * FROM painel_monitoracao) b ON a.id_not = b.id_notificacao
You cannot use a column alias again in the FROM clause or the WHERE clause after the SELECT (and possibly not other clauses as well, depending on the database).
So, repeat the expression:
SELECT *, REPLACE(a.id_notificacao, 'RIxRE', '') AS id_not
FROM robo_qualinet_cadastro_remedy rqcr JOIN
painel_monitoracao pm
ON REPLACE(rqcr.id_notificacao, 'RIxRE', '') = pm.id_notificacao;
Notes:
Use table aliases the mean something, such as abbreviations for the able names.
The subquery is not necessary in the FROM clause.
I suspect that you have a problem with your data model if you need a REPLACE() for the JOIN condition, but that is a different issue from this question.
I get that I should add alias with all the columns and I'm doing so but I'm still getting error.
CREATE TABLE MENTIONS AS SELECT
UM.USER_ID AS U_ID,
UM.SCREEN_NAME AS USER_SCREEN_NAME,
UM.MENTION_ID AS M_USER_ID,
(
SELECT
UI.USER_SCREEN_NAME AS MENTIONED_USER
FROM
USER_INFO UI
WHERE
UI.USER_ID = UM.MENTION_ID
AND ROWNUM = 1
)
FROM
USER_MENTION UM
USER_MENTION table
USER_ID SCREEN_NAME MENTION_ID
135846337 irisschrijft 774759032636727300
50117969 Chjulian 13769472
14411827 thenriques45 13769472
26681613 ahenotri 252074645
26681613 ahenotri 9796472
158378782 SpringerOpen 9796472
144241914 Kumarappan 252074645
User_INFO table:
USER_ID USER_SCREEN_NAME
22553325 jasonesummers
23435691 QRJAM false
67421923 inTELEgentMSP
97393397 knauer0x
85303739 MarriageTheorem
3842711 seki
3036414608 Bayes_Rule
838677852 BOLIGATOR
I'm still getting the above mentioned error, what am I doing wrong?
Lookup the Oracle Error Message Manual of the current Oracle version. Here the error is mentioned but without additional information.
In such a case look up the
Oracle Error Message Manual of version 9i
For reasons I don't know a lot of error messages have a description in the 9i manual but not in the manuals of higher versions. 9i is a rather old version so the description may be out of date. But it may contain valuable hints.
ORA-00998 must name this expression with a column alias
Cause: An expression or function was used in a CREATE VIEW statement, but no corresponding column name was specified. When expressions or functions are used in a view, all column names for the view must be explicitly specified in the CREATE VIEW statement.
Action: Enter a column name for each column in the view in parentheses after the view name.
We don't have a view but a a table that was created by a select. And actually the last expression of the select list is an expression without an alias. So try your statement using an alias for the last expression. So try
CREATE TABLE MENTIONS AS SELECT
UM.USER_ID AS U_ID,
UM.SCREEN_NAME AS USER_SCREEN_NAME,
UM.MENTION_ID AS M_USER_ID,
(
SELECT
UI.USER_SCREEN_NAME
FROM
USER_INFO UI
WHERE
UI.USER_ID = UM.MENTION_ID
AND ROWNUM = 1
) AS MENTIONED_USER
FROM
USER_MENTION UM
The column alias in the inner select list is useless and can be removed.
The problem with your query is that each column in the create table needs to have a name. You think you are assigning a name in the sub-select. However, you are not.
The subquery is just returning a value -- not a value with a name. So, the AS MENTIONED_USER in your version does nothing. This is a bit tricky, I guess. One way to think of the scalar subquery is that it is just another expression or function call. Things that happen inside it don't affect the outer query -- except for the value being returned.
The correct syntax is to put the column alias outside the subselect, not inside it:
CREATE TABLE MENTIONS AS
SELECT UM.USER_ID AS U_ID, UM.SCREEN_NAME AS USER_SCREEN_NAME, UM.MENTION_ID AS M_USER_ID,
(SELECT UI.USER_SCREEN_NAME
FROM USER_INFO UI
WHERE UI.USER_ID = UM.MENTION_ID AND ROWNUM = 1
) AS MENTIONED_USER
FROM USER_MENTION UM;
The following is my sql statement for a join in dB2.
select name, address, bloodgroup
from user_tb, health_tb
where user_tb.id = health_tb.id;
I am getting the following error:
"health_tb.id" is not valid in the context where it is used..
SQLCODE=-206, SQLSTATE=42703, DRIVER=4.12.79
I understand that one reason why I could be getting this error is because id may not exist in health_tb, but that is not the case. I hope someone can advise. Thank you.
First, you should learn to use modern join syntax, although this has nothing to do with your problem:
select name, address, bloodgroup
from user_tb join
health_tb
on user_tb.id = health_tb.id;
A simple search on Google pointed me to the documentation for this error. One of the first things it mentions is:
Possible reasons for this error include:
The specified column is not a column of any of the source or target
tables or views of the statement.
In a SELECT or DELETE statement, the specified column is not a column of any of the tables or views that are identified in a FROM
clause in the statement.
A column list of an SQL data change statement specified the name of a column of the target table or view of the statement.
I suspect that the id column is really called something like user_id. The working query might look like:
select name, address, bloodgroup
from user_tb join
health_tb
on user_tb.id = health_tb.user_id;
1) check if the id column in both tables have the same data type
2) check if there is any trailing space in the column name
select '<' || column_name || '>' from user_tab_columns
where tbname = 'health_tb'
If the id columns are defined as different types, that could be a problem.
Error: Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.
I understand this error, but I don't know how to rewrite the query to avoid it. I'm looking for records with duplicate values in f1, f2, and f3 based on the timestamp of the file they were imported from. The records not in the subquery should be modified as indicated. I don't need the import_file_timestamp in my results but I believe I have to include it to select the proper version of the record. The subquery, by itself, returns the correct information. How do I do this?
update import_raw_records
set raw_record_status = 'I'
from import_raw_records
where f1+f2+f3 NOT IN (
select a.f1+a.f2+a.f3,
max(b.import_file_timestamp)
from import_raw_records a
inner join import_files b
on a.import_file_id = b.import_file_id
group by a.f1+a.f2+a.f3)
Thanks,
John
I have a simple SQL query where a comparison is done between two tables for mismatching value.
Yesterday, we picked up an issue where one field was null and the other wasn't, but a mismatch was not detected.
As far as I can determine,the logic has been working all along until yesterday.
Here is the logic of the SQL:
CREATE TABLE Table1
(UserID INT,PlayDate DATETIME)
CREATE TABLE Table2
(UserID INT,PlayDate DATETIME)
INSERT INTO Table1 (UserID)
SELECT 5346
INSERT INTO Table2 (UserID,PlayDate)
SELECT 5346,'2012-11-01'
SELECT a.UserID
FROM Table1 a
INNER JOIN
Table2 b
ON a.UserID = b.UserID
WHERE a.PlayDate <> b.PlayDate
No values are returned even though the PlayDate values are different.
I have now updated the WHERE to read:
WHERE ISNULL(a.PlayDate,'') <> ISNULL(b.PlayDate,'')
Is there a setting in SQL which someone could have changed to cause the original code to no longer pick up the difference in fields?
Thanks
NULL <> anything
is unknown not true. SQL uses three valued logic (false/true/unknown) and the predicate needs to evaluate to true in a where clause for the row to be returned.
In fact in standard SQL any comparison with NULL except for IS [NOT] NULL yields unknown. Including WHERE NULL = NULL
You don't state RDBMS but if it supports IS DISTINCT FROM you could use that or if you are using MySQL it has a null safe equality operator <=> you could negate.
You say you think it previously behaved differently. If you are on SQL Server you might be using a different setting for ANSI_NULLS somehow but this setting is deprecated and you should rewrite any code that depends on it anyway.
You can simulate IS DISTINCT FROM in SQL Server with WHERE EXISTS (SELECT a.PlayDate EXCEPT SELECT b.PlayDate)
Not even a NULL can be equal to NULL.
Here are two common queries that just don’t work:
select * from table where column = null;
select * from table where column <> null;
there is no concept of equality or inequality, greater than or less
than with NULLs. Instead, one can only say “is” or “is not”
(without the word “equal”) when discussing NULLs.
- The correct way to write the queries
select * from table where column IS NULL;
select * from table where column IS NOT NULL;