I'm familiar that you can change tables using the ALTER TABLE statement. Is there a way to do the same for queries e.g. ALTER QUERY? I'm trying to change a field name from Expr1 to "MeaningfulFooNameField".
Something along the lines of:
"ALTER QUERY qryFoo RENAME COLUMN Expr1 to MeaningfulFooNameField;"
I can't do this manually as there are hundreds of tables to go through to keep the data definition consistent.
Related
I'm trying to write a query that RENAMEs multiple table columns at once. According to the documentation, the syntax is:
ALTER TABLE table_name
RENAME old_col_a AS new_col_a
, RENAME old_col_b AS new_col_b...;
However, in doing so I get a syntax error located on the comma after the first RENAME clause:
ERROR: syntax error at or near ","
LINE 3: , RENAME
^
SQL state: 42601
Character: 1
The query works for multiple DROP/ALTER/ADD columns and for single RENAMEs. I just can't for the life of me figure out why this error is occurring.
You need to use multiple ALTER statements:
ALTER TABLE table_name
RENAME COLUMN old_col_a TO new_col_a;
ALTER TABLE table_name
RENAME COLUMN old_col_b TO new_col_b;
ALTER TABLE
All the forms of ALTER TABLE that act on a single table, except RENAME, SET SCHEMA, ATTACH PARTITION, and DETACH PARTITION can be combined into a list of multiple alterations to be applied together. For example, it is possible to add several columns and/or alter the type of several columns in a single command. This is particularly useful with large tables, since only one pass over the table need be made.
I have to create a Datamodel at work with 29 Tables. A lot of tables have the same colums like "version year". Now I was wondering if theres a way to create a function which would add these columns to a Table.
Is this possible with transact-sql for a MS SQL Server? Or dose someone have a good idea?
You can not add columns to multiple tables in a single SQL statement, but you can easily create a multi-statement SQL that adds the columns to the desired table (copy-paste ftw!):
ALTER TABLE Table1 ADD COLUMN [Version year] int
ALTER TABLE Table2 ADD COLUMN [Version year] int
ALTER TABLE Table3 ADD COLUMN [Version year] int
...
...and so on
If you want to add a column to all of your tables, then you can use the undocumented sp_MSforeachtable procedure, or some kind of dynamic sql generation and EXEC or sp_executesql.
You can select the column information from the sys.columns and sys.tables views.
Based on your requirements, these solution could be much more difficult than the copy-paste one.
I have database and some text fields are CLOB type, I need to change most of these into VARCHAR2.
Have tried to do that using SQL Developer tool, by clicking edit on table, but get error like this one:
The following SQL statement failed:
ALTER TABLE TBL_PEOPLE MODIFY (PERSON VARCHAR2(150) )
Want to ask, how can this change be done
You can't, directly. The code you tried will have got an `ORA-22859, presumably. (It's helpful to show the actual errors you get, of course).
You'll need to add a new varchar2 column; copy the data across - or a substring of it if it might be larger than the new column you're creating; drop the clob column. You can rename the columns so it looks fairly transparent.
As in this SQL Fiddle:
alter table tbl_people rename column person to clob_person;
alter table tbl_people add (person varchar2(150));
update tbl_people set person = clob_person;
alter table tbl_people drop column clob_person;
Obviously don't drop the old column until you're sure the data has copied without errors. Also take into account any constraints, indexes, etc. that might exist in the old column; they will need to be recreated. And anything that references the old column will have been invalidated - generally procedures will recompile themselves on next use.
So be careful, test it first, and plan some down time.
ALTER TABLE tablename ADD (FIELD_LIST_TEMP VARCHAR2);
UPDATE tablename SET FIELD_LIST_TEMP = FIELD_LIST;
ALTER TABLE tablename DROP COLUMN FIELD_LIST;
ALTER TABLE tablename RENAME COLUMN FIELD_LIST_TEMP TO FIELD_LIST;
Here FIELD_LIST existing column which is defined it as CLOB. With above query it will change from CLOB to VARCHAR2.
I have a sql table that I am trying to add a column from another table to. Only when I execute the alter table query it does not pull the values out of the table to match the column where I am trying to make the connection.
For example I have column A from table 1 and column A from table 2, they are supposed to coincide. ColumnATable1 being an identification number and ColumnATable2 being the description.
I tried this but got an error...
alter table dbo.CommittedTbl
add V_VendorName nvarchar(200)
where v_venkey = v_vendorno
It tells me that I have incorrect syntax... Anyone know how to accomplish this?
alter table dbo.CommittedTbl
add V_VendorName nvarchar(200);
go
update c
set c.V_VendorName = a.V_VendorName
from CommittedTbl c
join TableA a
on c.v_venkey = a.v_vendorno;
go
I'm just guessing at your structure here.
alter table 2 add column A <some_type>;
update table2 set column A = (select column_A from table2 where v_venkey = v_vendorno);
Your names for tables and columns are a bit confusing but I think that should do it.
There is no WHERE clause for an ALTER TABLE statement. You will need to add the column (your first two lines), and then insert rows based upon a relationship you define between the two tables.
ALTER TABLE syntax:
http://msdn.microsoft.com/en-us/library/ms190273%28v=sql.90%29.aspx
There are several languages within SQL:
DDL: Data Definition Language - this defines the schema (the structure of tables, columns, data types) - adding a column to a table affects the table definitions and all rows will have that new column (not just some rows according to a criteria)
DML: Data Manipulation Language - this affects data within a table, and inserting, updating or other changes fall into this and you can update some data according to criteria (and this is where a WHERE clause would come in)
ALTER is a DDL statement, while INSERT and UPDATE are DML statements.
The two cannot really be mixed as you are doing.
You should ALTER your table to add the column, then INSERT or UPDATE the column to include appropriate data.
Is it possible that you want a JOIN query instead? If you want to join two tables or parts of two tables you should use JOIN.
have a look at this for a start if you need to know more LINK
hope that helps!
I want to create a DTS Package to pull data from an Oracle table into a SQL2K
table. How can I insert rows that are not already in the SQL2K table and
update rows that already exist in the SQL2K table?
I guess I could truncate and repopulate the entire table or create a
temporary table and then do updates/inserts from the temp table into the
destination table.
Is there any easier way using DTS?
Thanks,
Rokal
You can do that in a DTS package using two data driven query tasks: one for the inserts and one for the updates. The data driven query tasks are a bit of a pain to use, but they work. I've also done this (a "merge") in sql server 2000 with an AS/400 database using a dynamic t-sql. You'd write a t-sql script that outputs psql and runs it againt a linked server to the Oracle database.
UPDATE:
A DTS "data driven query task" will let you insert|update data from the sql server connection in DTS to an oracle server connection in DTS w/o a temp table or a linked server.
Update2; here's some more info on what I mean:
http://www.databasejournal.com/features/mssql/article.php/3315951
http://msdn.microsoft.com/en-us/library/aa933507(SQL.80).aspx
Are you keeping the same primary key values?
If you are you have a number of options, some versions of SQL support the MERGE statement which will update or insert just like you require.
Or you can write your own.
Something along the lines of loading all the rows into a staging table in your SQL database and row by row checking for the existence of your primary key in your main SQL table. If the key exists update the row and if not insert it.
Yes, the primary key values in the source and destination will match.
I was hoping to accomplish this task without the use of a temporary (staging) table.
Also, I am using sql server 2000 so the MERGE statement is not available.
Try:
DELETE FROM dbo.WhateverTable WHERE WhateverTableID IN (SELECT WhateverTableID FROM MySource)
It might be pretty slow, use join instead:
Delete a
from firstTable a join secondTable b on a.id = b.id
There's no way with TSQL to do a INSERT or UPDATE in the same statement, but you could very easily do it in two statements (as you mentioned above).
Statement 1:
DELETE FROM dbo.WhateverTable
WHERE WhateverTableID IN (SELECT WhateverTableID FROM MySource)
Statement 2:
INSERT INTO dbo.WhateverTable
SELECT * FROM MySource
Also, is there any reason why you don't want to use a temp table?