alter table add contraint (postgresql) - postgresql

Below I have a string I am attempting to execute in postgres, but I am receiving an SQL state error (42601) which I understand to be a syntax issue.
I have checked through the documentation on executing this statement and feel as though I have it correct. Any syntactical suggestions in order to correct this statement would be greatly appreviated.
ALTER TABLE ASeriesResults ADD CONSTRAINT DF_ASeriesResults_CaseId
DEFAULT ((0)) FOR CaseId;

Why are you adding a constraint if you want a default value?
A default value is not a constraint (and I don't think anything in the manual suggests that you need add constraint to add a default value):
ALTER TABLE ASeriesResults ALTER COLUMN CaseId SET DEFAULT 0;

Related

Postgres ALTER TABLE ADD CONSTRAINT IF NOT EXISTS not working

I need to add a Constraint if not exists and am hitting the following error. Note that a similar if not exists for a new Column, right above it, does work. There's some syntax error when adding a Constraint, am I missing something?
alter table requests_t
add constraint if not exists
valid_bias_check CHECK (bias_flag::text = ANY (ARRAY['Y'::character varying::text, 'N'::character varying::text]));
Error
ERROR: syntax error at or near "not"
LINE 2: add constraint if not exists
Since Postgres doesn't support this syntax with constraints (see a_horse_with_no_name's comment), I rewrote it as:
alter table requests_t
drop constraint if exists valid_bias_check;
alter table requests_t
add constraint
valid_bias_check CHECK (bias_flag::text = ANY (ARRAY['Y'::character varying::text, 'N'::character varying::text]));

Setting multiple alter statements on a single column in one command SQL

I am trying to modify a column data type and name in one command.
Is it possible to apply multiple alter statements on one column in one code line? Is that the correct syntax?
ALTER TABLE tb_table
ALTER COLUMN colum_date
SET DATA TYPE TIMESTAMP NOT NULL
RENAME COLUMN colum_date TO colum_timestamp;
I have been looking for related bibliography but could not find much information on the web.
According to the documentation renaming a column is an action that cannot be combined with others but requires its own statement. So no, you cannot do what you want in one statement.
But you can do it in one transaction. Setting the datatype and setting the NOT NULL constraint requires two actions though. But both of that actions can be in one statement.
BEGIN TRANSACTION;
ALTER TABLE tb_table
ALTER COLUMN colum_date
SET DATA TYPE TIMESTAMP,
ALTER COLUMN colum_date
SET NOT NULL;
ALTER TABLE tb_table
RENAME COLUMN colum_date
TO colum_timestamp;
COMMIT TRANSACTION;

With Check Option Postgresql

I have an ALTER TABLE statement, written in T-SQL (SQL Server):
ALTER TABLE myTable WITH CHECK ADD CONSTRAINT [FK_myTable_myColumn] FOREIGN KEY(myColumn) REFERENCES otherTable (Column)
If I want to translate this statement in Postgresql, how can I make this? Paying attention to WITH CHECK ADD CONSTRAINT
You need to
remove WITH CHECK - I don't know what this is supposed to do, but you can't have a "check constraint" together with a foreign key constraint in Postgres
use standard compliant identifiers (without the square brackets)
ALTER TABLE my_table
ADD CONSTRAINT fk_mytable_mycolumn
FOREIGN KEY(my_column) REFERENCES other_table (column)

equivalent for enable and disable validate and novalidate in db2

I want to enable constraint but don't validate existing record. only validate future record in db2.
This should be apply for check constraint.
alter table table_name add check (column_name <> '')
DB2 hast the ENFORCED and NOT ENFORCED options for check constraints. The syntax for constraints is part of the CREATE TABLE and ALTER TABLE statements. A sub-option is to either set TRUSTED or NOT TRUSTED depending on the quality of your data.
Something like the following should work:
alter table mytable add check (column1>myvalue) not enforced trusted
try Something like this
ALTER TABLE YOURLIB.YOURTABLE DROP CONSTRAINT YOURLIB.YOURCONSTRAINTNAME1;
ALTER TABLE YOURLIB.YOURTABLE ADD CONSTRAINT YOURLIB.YOURCONSTRAINTNAME1 CHECK (YOUCOLUMNNAME<>'') NOT ENFORCED TRUSTED;

ALTER TABLE SET DEFAULT and DROP DEFAULT are not allowed for tables

i want to ask one question about db2 sql.
when i runnig this ddl to set default value
alter table TTKR.TKR_TableName
alter TKR_column_name set default '1111-11-11'
i am getting this error and search on google i saw that reason is
650
THE ALTER STATEMENT CANNOT BE EXECUTED, REASON reason-code
reason code 22
`"ALTER TABLE SET DEFAULT and DROP DEFAULT are not allowed for tables referenced by a materialized query table or view.`"
how can i fix it ?