I want to check if there is one particular field exists in different table using one query only?
For example, I have 3 tables, with many fields. I want to check if field A in table 1 exists in table 2 and table 3.
How can I do it?
Many thanks!
You can use COLUMNS view:
SELECT *
FROM my_dataset.INFORMATION_SCHEMA.COLUMNS
WHERE column_name = "fieldA_name"
and table_name in ("table1_name", "table2_name", "table3_name")
Related
I have a table that has a primary key WORKITEMID, and the following 3 foreign keys PRODSERVID,PROCESSID,and TASKKNOWID.
I have a view that I can create that also has PRODSERVID,PROCESSID, AND TASKKNOWID. This view will usually have ALL the records in above table plus some new ones - not in the table. The 'table' by definition is meant to hold the unique combinations of PRODSERVID, PROCESSID, and TASKKNOWID.
I would like to insert from the view into the table any new combinations in the view not present in the table. And I don't want to overwrite the existing WORKITEMIDs in the INSERT- because those WORKITEMIDs are used elsewhere.
Can this be done in SQL?
Thanks
Absolutely, the simplest form of criteria for this is to use the negation of EXISTS()
INSERT INTO [TableName] (PRODSERVID,PROCESSID,TASKKNOWID,... )
SELECT PRODSERVID,PROCESSID,TASKKNOWID,...
FROM [ViewName] v
WHERE NOT EXISTS (
SELECT 1 FROM [TableName] t
WHERE t.PRODSERVID = v.PRODSERVID AND t.PROCESSID = v.PROCESSID AND t.TASKKNOWID = v.TASKKNOWID
)
replace the ... with your other fields
You could also use a non-corellating outer join but I find not exists makes the intent much clearer.
There is a good comparison of the different approaches to this issue in this article: T-SQL commands performance comparison – NOT IN vs SQL NOT EXISTS vs SQL LEFT JOIN vs SQL EXCEPT
I have a table that was created importing data from an Excel spreadsheet. The table currently looks like this:
I would like to either retrieve the column name from every row or either create a new table with a couple of columns, Data and ColumnName
So, being more clear, ABAS-3 for example is under ClinicalPsycology column, I'd like to create a temporary table or at least return in a query the column name for ABAS-3.
The ideal for me would be to create a temporary table that looks like this:
Data ColumnName
---------------------------
ABAS-3 ClinicalPsycology
ADHDT-2 ClinicalPsycology
AAB SpecialEducation
SAGES-3 Counseling
... and like that.. is that possible?
A general way to do this in any database is to use union all:
select ClinicalPsycology as data, 'ClinicalPsycology' as column
from t
union all
select SpecialEducation as data, 'SpecialEducation' as column
from t
union all
. . .;
Some databases support lateral joins (via the lateral or apply keywords). Such methods would be more efficient than using union all on each column.
I want to merge the IndirectFlights table to the PriceTable.
I do not have IDs entered in the SourceTable (IndirectFlights) and I haven't set a PK for it yet.
The ID column for the PriceTable is an Identity (1,1) column and is also the Primary Key.
Qs1 How do I enter IDs in Source column so that they dont clash with target table (PriceTable) IDs? I was thinking of using a sequence but It potentially could clash in future.
Qs2 Can I choose what columns to merge or must I merge all the columns from the Source table?
Target Table (PriceTable) Columns
IDAirport_ICAO_Code,Airline_ICAO_Code,Departure,Price,RouteStatus,DateRowModified
Source Table (IndirectFlights) Columns
IDAirport_ICAO_Code,Destination,Airline,Airline_ICAO_Code,RouteStatus,Connecting Airport
Edit: I have just run the following Union All statement as an alternative to using Merge.
Select ID,Airport_ICAO_Code,Airline_ICAO_Code,RouteStatus
From RoughworkPriceTable
Union All
Select ID,Airport_ICAO_Code,Airline_ICAO_Code,RouteStatus
From RoughworkIndirectFlights;
The code worked but i noticed that the ID column accepted the Null values from IndirectFlights.ID eventhough I have the ID columns set to Not Null.
Can anyone explain this.
Also can someone expalin how I could create a new permanent table from this Union All statement.
You can create a new table with something like
Select * into newTmpTable from (
Select ID,Airport_ICAO_Code,Airline_ICAO_Code,RouteStatus From RoughworkPriceTable
Union All
Select ID,Airport_ICAO_Code,Airline_ICAO_Code,RouteStatus From RoughworkIndirectFlights)
as mergedData;
I had to make a new table to get the Include statement working in Entity Framework since EF was looking for a table called be_PostTagbe_Posts. I was using EF Code First from DB. But now the question is about SQL. I added one row of data and now the include works. But what I am looking for is a SQL command that can copy data from 1 column in 1 table and 1 column in another into the new be_PostTagbe_Posts table. In the be_Posts table I need the data in PostRowID to go into be_Posts_PostRowID and PostTagId to go into be_PostTag_PostTagID. Both be_PostTag_PostTagID and be_Posts_PostRowID are in the new be_PostTagbe_Posts table. I am not very good with SQL so not sure how to do this.
Edit: Thanks for the answers. I tried 2 separate queries but only data was inserted into the the be_PostTag_PostTagID while be_PostTag_PostRowID remained null.
And I tried this query which returned The multi-part identifier "be_PostTag.PostID" could not be bound.
INSERT INTO be_PostTagbe_Posts(be_PostTag_PostTagID, be_Posts_PostRowID)
SELECT be_PostTag.PostTagID, be_Posts.PostRowID
WHERE be_PostTag.PostID = be_Posts.PostID
EDIT:
This only inserted half the data - even 2 inserts leave one column null
INSERT INTO be_PostTagbe_Posts (be_Posts_PostRowID)
SELECT PostRowID FROM be_Posts;
INSERT INTO be_PostTagbe_Posts (be_PostTag_PostTagID)
SELECT PostTagID FROM be_PostTag;
And yet management studio tells me the query executed successfully but one column is still null. Weird.
Here are screenshots of the tables:
SELECT PostTagID AS be_PostTag_PostTagID, PostRowID AS be_Posts_PostRowID
INTO be_PostTagbe_Posts
FROM be_PostTag
Inner JOIN be_Posts
ON be_PostTag.PostID=be_Posts.PostID
That command created the new table with the 2 columns populated.
If i understand you ,you want to Copy Table Z's Column A to Table X And Table Z's Column B to Table Y.
If it is so, According to your question it is not clear about Table Structure of TableX and TableY
Assuming TableX And TableY to single ColumnTable [Apart from IdentityColumn] our query will be
INSERT INTO TableX
SELECT ColumnA FROM TableZ
INSERT INTO TableY
SELECT ColumnB FROM TableZ
Rest put your Entire Structure of Table To Get More Help Because These query are on Assumptions
There's not enough information in your question to give you a working example, but this would be the general syntax for INSERTing into a different table using a query SELECTing from two other tables.
INSERT INTO destination_table(wanted_value_1, wanted_value_2)
SELECT table_1.source_field_1, table_2.source_field_1
WHERE table_1.matching_field = table_2.matching_field
There has to be some sort of relationship between the two tables for the WHERE clause to work in that statement. I'm guessing based the little information you provided that there is a PostRowID field somewhere in the table that contains the tags such that your data would look similar to this in the tag table:
PostRowID PostTagID
--------- ---------
1 1
1 2
1 3
1 4
2 1
2 2
3 3
4 4
It sounds like you should use two sql statements:
Insert into `be_PostTagbe_Posts` (`be_PostTag_PostTagID`)
select `PostTagID` from POSTTAGIDTABLE
and
Insert into `be_PostTagbe_Posts` (`be_Posts_PostRowID`)
select `PostRowID` from POSTTAGIDTABLE
unless the items have some sort of relationship, then if you have a select statement that will select the merged data in two columns you can just do
Insert into `be_PostTagbe_Posts` (`be_PostTag_PostTagID`,`be_Posts_PostRowID`)
(select statement that selects the two items)
I have to write a statement which fills a table (customers) with synthetically generated values. There is an addtional constraint that I should only fill those attributes (columns) with a special property (i.e. formally do a projection on them and then operate on them exclusively). These properties are stored in a second table, attributes.
My first draft consists of the following two statements:
-- Get the attributes (columns) we are interested in only
SELECT attributeID from attributes
WHERE tableID = 'customers'
-- Iterate over each row of customers, filling only those attributes (columns)
-- obtained by the above SELECT statement
UPDATE customers
SET (use the records from above select statement...)
Now my problem is how to put them together. I know there is the possibility of appending a WHERE clause to the SET clause, but that would select rows, not columns, as I need. I also read about PIVOT, but so far only inside one single table, not two, as is the case here. I would be very thankful for any hint, since I have no idea how to do this.
is not it you're looking for?
SQL Update Multiple Fields FROM via a SELECT Statement
UPDATE
Table
SET
Table.col1 = other_table.col1,
Table.col2 = other_table.col2
FROM
Table
INNER JOIN
other_table
ON
Table.id = other_table.id
Standard SQL-92 requires a scalar subquery:
UPDATE customers
SET attributeID = (
SELECT A1.attributeID
FROM attributes AS A1
WHERE A1.tableID = 'customers'
);
However, UPDATE customers...WHERE A1.tableID = 'customers' "smells" like you may be mixing data with metadata.