Source have some column like ID, Name, Phone and Address and destination has same column but one extra column Operator and want to put static text there during lookup transformation.Our destination has composite primary key ID+Operator.
I tried lookup transformation and working well.but want to add static text during lookup transformation.
...
...
check the destination table if column Operator accept NULL value
Regards
Related
i got a table with three columns whose type is BYTES
i succeed to make a SELECT SAFE_CONVERT_BYTES_TO_STRING
but now, i wish i could REPLACE my BYTES values by their corresponding STRING in my original table
Replacing the value would imply changing the column type, which is not supported.
My recommendation would be to save your query results to a different destination table then drop the current table and copy the destination table to rename it as the original one.
How can i create a table, that allows only to put data in NAME, if the data matches with the data that i want to be allowed in NAME. So like Bla1 or Bla2.
CREATE TABLE Table1 (
NAME VARCHAR(23)
NAME has to be one of them: ('Bla1', 'Bla2')
)
The best way to do it is probably to have a second table with all the allowed names in it, and making a FOREIGN KEY from the name field in your Table1 to the name field in that other table. That'll automatically fail any insert queries for which the name is not contained in the list of allowed names.
This has an advantage over things like ENUM and such in that it does not require you to rebuild your table (which is a very expensive operation) every time you want to allow another name and it also allows you to later add additional related info to each name by adding it to the other table.
Here's a great article on why using a foreign key is much better than using enums or other such checks in the table itself: http://komlenic.com/244/8-reasons-why-mysqls-enum-data-type-is-evil/
Try this:
CREATE TABLE Table1 (
name VARCHAR(23) CHECK( name IN ('Bla1','Bla2') )
);
I am working in SQL Server 2008. I have a table with many columns that will not have values (at least, for the given situation). So, they will have a NULL value when I query each of them. I would like to instead make these NULL values be empty strings (i.e., ''). What is the best way to achieve this? My current idea is to set a DEFAULT value of '' on each them at the time that the table is created. However, since there are so many of them, this will be very tedious.
You have 2 options:
As you said, give it a default value of empty string for columns you don't want to be null when you create table/add new columns.
When you select nullable columns from the table you can use IsNull(ColumnName,'') which means if ColumnName is null it'll return empty string ('').
Create a table with the same structure as your current table, with a different name, and the default value as ''.
Insert into that table from your original table.
Delete the original table.
Change the name of the new table to the original table name.
In pgsql, is there a way to have a table of several values, and choose one of them (say, other_id), find out what its highest value is and make every new entry that is put in the table increment from that value.
I suppose this was just too easy to have had a chance of working..
ALTER TABLE address ALTER COLUMN new_id TYPE SERIAL
____________________________________
ERROR: type "serial" does not exist
Thanks much for any insight!
Look into postgresql documentation of datatype serial. Serial is only short hand.
CREATE TABLE tablename (
colname SERIAL
);
is equivalent to specifying:
CREATE SEQUENCE tablename_colname_seq;
CREATE TABLE tablename (
colname integer NOT NULL DEFAULT nextval('tablename_colname_seq')
);
ALTER SEQUENCE tablename_colname_seq OWNED BY tablename.colname;
This happened because you may use the serial data type only when you are creating a new table or adding a new column to a table. If you'll try to ALTER an existing table using this data type you'll get an error. Because serial is not a true data type, but merely an abbreviation or alias for a longer query.
In case you would like to achieve the same effect, as you are expecting from using serial data type when you are altering existing table you may do this:
CREATE SEQUENCE my_serial AS integer START 1 OWNED BY address.new_id;
ALTER TABLE address ALTER COLUMN new_id SET DEFAULT nextval('my_serial');
The first line of the query creates your own sequence called my_serial. The
OWNED BY statement connects the newly created sequence with the exact column of your table. In your case the table is address and the column is new_id.
The START statement defines what value this sequence should start from.
The second line alters your table with the new default value, which will be determined by the previously created sequence.
It will give you the same result as you were expecting from using serial.
A quick glance at the docs tells you that
The data types smallserial, serial and bigserial are not true types
but merely a notational convenience for creating unique identifier columns
If you want to make an existing (integer) column to work as a "serial", just create the sequence by hand (the name is arbitrary), set its current value to the maximum (or bigger) of your current address.new_id value, at set it as default value for your address.new_id column.
To set the value of your sequence see here.
SELECT setval('address_new_id_seq', 10000);
This is just an example, use your own sequence name (arbitrary, you create it), and a number greater than the maximum current value of your column.
Update: as pointed out by Lucas' answer (which should be the acccepted one) you should also specify to which column the sequence "belongs to" by using CREATE/ALTER SEQUENCE ... OWNED BY ...
certain fields in our database contain calculated functions e.g.
select lastname + ', ' + firstname as fullname from contact where contact.id =$contact$
when viewing the field the correct data is shown (i assume this is because when you open the record, the calculation is executed). however, the data is not 'stored' to the field, and therefore is null until the record is opened. is it possible to 'store' the result to the field, making it possible to search the data?
many thanks
james
EDIT
it is not possible for me to create computed_columns using our software.
the above field is a text feild where either 1) a user can manual type in the required data or 2) the database can generate the answer for you (but only whilst you are looking at the record). i know that if I run the following:
Select * from contact where contact.id =$contact$ for xml auto
i only get lastname, firstname - so i know that the fullname field does not retain its information.
If you are using computed columns in sql server, the column is already searchable regardless of whether the calculation result is stored or not. However, if you would like to make it so that the calculation is not run each time you read the row, you can change that under row properties in your Modify Table GUI.
Use the PERSISTED key word when you create the column
From BOL:
PERSISTED
Specifies that the SQL Server Database Engine will physically store the computed values in the table, and update the values when any other columns on which the computed column depends are updated. Marking a computed column as PERSISTED lets you create an index on a computed column that is deterministic, but not precise. For more information, see Creating Indexes on Computed Columns. Any computed columns that are used as partitioning columns of a partitioned table must be explicitly marked PERSISTED. computed_column_expression must be deterministic when PERSISTED is specified.
This isn't the way computed columns work in SQL Server, so I suspect this is something your client application is doing. How are you looking at the data when the value is computed correctly? Does it work when you view the data in SSMS?
Take a look at http://msdn.microsoft.com/en-us/library/ms191250(v=SQL.90).aspx to see how to create computed columns properly.
eg.
create table TestTable
(a int,
b int,
c as a + b)
insert into TestTable (a,b)
values (1,2)
select * from TestTable
where c = 3
This query is based on the computed column and it returns the row that's been inserted.
You need to use the PERSISTED option on a column when you use CREATE TABLE e.g.
CREATE TABLE test (col_a INT, col_b INT, col_c AS col_A * col_B PERSISTED)