CREATE VIEW ALL_TABLES AS SELECT * FROM employee_view, av_pay;
I keep getting error message how do I overcome this
VIEW Duplicate column name 'ISLAND'
av_pay:
employee_view:
You are doing a select *, which will output the same column names as defined in the tables you are querying. As you have both columns defined with the same name in both, there you have the error.
So either rename one of the columns or change the query to something like:
select employee_view.ISLAND ISLAND_V, av_pay.ISLAND ISLAND_P, ... FROM ...
The db engine complaints because your select clause is "*" and both the source tables contain the column "island". As a result, the dbms does not know which column should be returned - from employee_view or av_pay?
BTW, a select from 2 tables without a join will result in a cartesian product...
Related
In this query I inserting records into a new empty table I created. These records are derived from another table where I am left joining that table to itself, in order to output records that are not included in the recent table that is appended on top of an older table. So basically it outputs records that were deleted.
CREATE DEFINER=`definer` PROCEDURE `stored_procedure_name`()
MODIFIES SQL DATA
SQL SECURITY INVOKER
BEGIN
START TRANSACTION;
INSERT INTO exceptions_table (
`insert_date`,
`updated`,
`account_number`,
`id_number`)
SELECT
`insert_date`,
`updated`,
`account_number`,
`id_number`
FROM original_table ot1
LEFT JOIN original_table ot2
ON ot1.`account_number` = vdcaas2.`account_number`
AND ot2.`insert_date` = '2022-12-20'
WHERE ot1.`insert_date` = '2022-12-10'
AND ot2.`account_number` IS NULL;
COMMIT;
END
I get an error stating: "SQL Error: Column "insert_date" in field list is ambiguous.
I'm not sure why because I have specified which table I am grabbing "insert_date" from when INSERTING and when SELECTING and JOINING..
Every row in your query has two columns called insert_date: one from the table you've aliased as "ot1", and one from the table (as it happens, the same table) you've aliased as "ot2".
The database system doesn't know which one you want, so you have to tell it by writing either "ot1.insert_date" or "ot2.insert_date", just as you do elsewhere in the query:
... ot2.`insert_date` = '2022-12-20'
...
... ot1.`insert_date` = '2022-12-10'
The same is true of the other columns you've listed to select.
You need to change this
SELECT
`insert_date`,
`updated`,
`account_number`,
`id_number`
to this
SELECT
ot1.`insert_date`,
ot1.`updated`,
ot1.`account_number`,
ot1.`id_number`
or this
SELECT
ot2.`insert_date`,
ot2.`updated`,
ot2.`account_number`,
ot2.`id_number`
or some combination
Issue
SQL Error: Column "insert_date" in field list is ambiguous error means that the query is trying to reference the "insert_date" column from both tables, ot1 and ot2.
Try the following:
SELECT
ot1.`insert_date`,
ot1.`updated`,
ot1.`account_number`,
ot1.`id_number`
Also, you have a typo in your query:
ON ot1.`account_number` = vdcaas2.`account_number` -> ON ot1.`account_number` = ot2.`account_number`
How would the SQL statement look like to return the bottom result from the upper table?
The last letter from the key should be removed. It stands for the language. EXP column should be split into 5 columns with the language prefix and the right value.
I'm weak at writing more or less difficult SQL statements so any help would be appreciated!
The Microsoft Access equivalent of a PIVOT in SQL Server is known as a CROSSTAB. The following query will work for Microsoft Access 2010.
TRANSFORM First(table1.Exp) AS FirstOfEXP
SELECT Left([KEY],Len([KEY])-2) AS [XKEY]
FROM table1
GROUP BY Left([KEY],Len([KEY])-2)
PIVOT Right([KEY],1);
Access will throw a circular field reference error if you try to name the row heading with KEY since that is also the name of the original table field that you are deriving it from. If you do not want XKEY as the field name, then you would need to break apart the above query into two separate queries as shown below:
qsel_table1:
SELECT Left([KEY],Len([KEY])-2) AS XKEY
, Right([KEY],1) AS [Language]
, Table1.Exp
FROM Table1
ORDER BY Left([KEY],Len([KEY])-2), Right([KEY],1);
qsel_table1_Crosstab:
TRANSFORM First(qsel_table1.Exp) AS FirstOfEXP
SELECT qsel_table1.XKEY AS [KEY]
FROM qsel_table1
GROUP BY qsel_table1.XKEY
PIVOT qsel_table1.Language;
In order to always output all language columns regardless of whether there is a value or not, you need to spike of those values into a separate table. That table will then supply the row and column values for the crosstab and the original table will supply the value expression. Using the two query solution above we would instead need to do the following:
table2:
This is a new table with a BASE_KEY TEXT*255 column and a LANG TEXT*1 column. Together these two columns will define the primary key. Populate this table with the following rows:
"AbstractItemNumberReportController.SelectPositionen", "D"
"AbstractItemNumberReportController.SelectPositionen", "E"
"AbstractItemNumberReportController.SelectPositionen", "F"
"AbstractItemNumberReportController.SelectPositionen", "I"
"AbstractItemNumberReportController.SelectPositionen", "X"
qsel_table1:
This query remains unchanged.
qsel_table1_crosstab:
The new table2 is added to this query with an outer join with the original table1. The outer join will allow all rows to be returned from table2 regardless of whether there is a matching row in the table1. Table2 now supplies the values for the row and column headings.
TRANSFORM First(qsel_table1.Exp) AS FirstOfEXP
SELECT Table2.Base_KEY AS [KEY]
FROM Table2 LEFT JOIN qsel_table1 ON (Table2.BASE_KEY = qsel_table1.XKEY)
AND (Table2.LANG = qsel_table1.Language)
GROUP BY Table2.Base_KEY
PIVOT Table2.LANG;
Try something like this:
select *
from
(
select 'abcd' as [key], right([key], 1) as id, expression
from table1
) x
pivot
(
max(expression)
for id in ([D], [E])
) p
Demo Fiddle
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.
Let's say that we have a table named Data with Id and Weather columns. Other columns in that table are not important to this problem. The Weather column can be null.
I want to display all rows where Weather fits a condition, but if there is a null value in weather then display null value.
My SQL so far:
SELECT *
FROM Data d
WHERE (d.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%' OR d.Weather IS NULL)
My results are wrong, because that statement also shows values where Weather is null if condition is not correct (let's say that users mistyped wrong).
I found similar topic, but there I do not find appropriate answer.
SQL WHERE clause not returning rows when field has NULL value
Please help me out.
Your query is correct for the general task of treating NULLs as a match. If you wish to suppress NULLs when there are no other results, you can add an AND EXISTS ... condition to your query, like this:
SELECT *
FROM Data d
WHERE d.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%'
OR (d.Weather IS NULL AND EXISTS (SELECT * FROM Data dd WHERE dd.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%'))
The additional condition ensures that NULLs are treated as matches only if other matching records exist.
You can also use a common table expression to avoid duplicating the query, like this:
WITH cte (id, weather) AS
(
SELECT *
FROM Data d
WHERE d.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%'
)
SELECT * FROM cte
UNION ALL
SELECT * FROM Data WHERE weather is NULL AND EXISTS (SELECT * FROM cte)
statement show also values where Wether is null if condition is not correct (let say that users typed wrong sunny).
This suggests that the constant 'sunny' is coming from end-user's input. If that is the case, you need to parameterize your query to avoid SQL injection attacks.
I'm performing a sql statement that selects a few columns from the table but for one column the query performs a IN select that returns rows which contain the requested values.
My problem is that typical users won't understand the values returned from the db so I want to rename the values so that they are returned (in a csv file) in the users understanding. Anyone help me?
The relevant section is as follows:
Select a.attr1, a.attr2, b.attr1, b.attr2, b.attr3
From table a, table b
Where b.attr1 IN ('val.1', 'val.2', 'val.3', 'val.4', 'val.5')
Thanks
Use a CASE statement to format them appropriately, something like:
SELECT CASE a.attr1
WHEN 'val.1' THEN 'myCustomVal1'
WHEN 'val.2' THEN 'myCustomVal2'
WHEN 'val.3' THEN 'myCustomVal3'
WHEN 'val.4' THEN 'myCustomVal4'
ELSE 'myCustomVal5'
END,
a.attr2, b.attr1, b.attr2, b.attr3
FROM table a, table b
WHERE b.attr1 IN ('val.1', 'val.2', 'val.3', 'val.4', 'val.5')