CREATE SCHEMA using a name stored - sql

I am trying to create a new schema on my postgres database which name is stored on an existing table, my query look like this:
CREATE SCHEMA (SELECT name FROM table)
But I am getting a syntax error. What am I doing wrong? Is this a valid way to create the new schema? Which other solution exist for this issue?

You can do it with dynamic sql:
do
$$
declare s_name text;
begin
-- make sure there is exactly one row in that table!
-- otherwise you need some where condition or an aggregat to ensure that.
SELECT name INTO s_name FROM some_table;
execute 'create schema '|| quote_ident(s_name);
end;
$$

It is not possible, create schema syntax required a valid schema name (i.e. valid schema name string). in your case it will throw exception as
********** Error **********
ERROR: syntax error at or near "("
SQL state: 42601
Character: 15

Related

Procedure (unknown) does not exist PostgreSQL

I'm new to PostgreSQL, and trying to learn about stored procedure with PostgreSQL. Here are the steps I followed.
Installed pgAdmin4
Created the Database
Created the table "Users" under public schema
Created the procedure "GetUserByEmail"
CREATE OR REPLACE PROCEDURE GetUserByEmail
(
Email Varchar(100)
)
LANGUAGE plpgsql AS
$$
BEGIN
Select * from public."Users" where "Email" = Email
END
$$;
When calling it from query tool, I get an error.
CALL public.GetUserByEmail('d#d.com')
ERROR: procedure public.getuserbyemail(unknown) does not exist LINE
1: CALL public.GetUserByEmail('d#d.com')
^ HINT: No procedure matches the given name and argument types. You might need to add explicit type casts. SQL state: 42883
Character: 6
Checked the permission, and the user has execution rights.
Tried different ways but not sure what is wrong.
Are PostgreSQL column names case-sensitive?
if you create table "users"(a int...) then you stick with "users" every time you select/update/delete "users" table.
You can easily imitate 38.5.9. SQL Functions Returning Sets(https://www.postgresql.org/docs/current/xfunc-sql.html)
CREATE FUNCTION getusers(text) RETURNS SETOF "users" AS $$
SELECT * FROM "users" WHERE email = $1;
$$ LANGUAGE SQL;
SELECT * FROM getusers('hi') AS t1;
stored procedure versus function
demo

How to compare two values in different tables with a TRIGGER SQL?

CREATE TRIGGER Comparer_Prix
BEFORE UPDATE ON ARTICLE
FOR EACH ROW BEGIN
SELECT ARTICLE.PRIXVENTE, ARTICLE.N_PRODUIT, ARTICLE.N_FABRICANT, LIEN_FABRICANT_PRODUIT.PRIXFABRICANT, LIEN_FABRICANT_PRODUIT.N_PRODUIT, LIEN_FABRICANT_PRODUIT.N_FABRICANT
FROM ARTICLE, LIEN_FABRICANT_PRODUIT
WHERE ARTICLE.N_FABRICANT=LIEN_FABRICANT_PRODUIT.N_FABRICANT AND ARTICLE.N_PRODUIT=LIEN_FABRICANT_PRODUIT.N_PRODUIT;
IF (NEW.PRIXVENTE< PRIXFABRICANT) THEN RAISE_APPLICATION_ERROR(-20001, 'Refusé');
END IF;
END;
I am trying to create a trigger that codes the following rule: the sales price must always be higher than the manufacturing price.
Here the errors I get:
Error(2,3): PL/SQL: SQL Statement ignored
Error(2,69): PL/SQL: ORA-00904: "LIEN_FABRICANT_PRODUIT"."PRIXFABRICANT" : invalid identifier
Error(2.92): PLS-00302: The component "PRIXFABRICANT" must be declared.
Error(5,3): PL/SQL: Statement ignored
Error(5,10): PLS-00201: the identifier 'NEW.PRIXVENTE' must be declared.
It is not new, but :new (you're missing a colon).
Though, that's not the only issue here; you can't select from a table which is just being modified; mutating table error is expected. Lucky you, you don't have to select from article as you can reference its values using the same :new value.
ORA-00904 means that you've used a column name which doesn't exist in that table. As you didn't post tables' descriptions, I'm simply repeating what you wrote. Fix it yourself.
Something like this:
create or replace trigger comparer_prix
before update on article
for each row
declare
l_prixfabricant lien_fabricant_produit.prixfabricant%type;
begin
select prixfabricant
into l_prixfabricant
from lien_fabricant_produit
where n_fabricatn = :new.n_fabricant
and n_produit = :new.n_produit;
if :new.prixvente < l_prixfabricant then
raise_application_error(-20001, 'Refusé');
end if;
end;
/
Also, it wouldn't harm if you learnt how to properly format code and make it easier to read. Use table aliases (instead of those lengthy table names).
If You compare two tables use:
... WHERE ... AND EXISTS(SELECT * FROM <TAB_COMPARE>)

How can I control execution of a SQL statement based on the DB2s structure?

We want to run a simple SQL statement (dropping and creating an index), but only if the old index has not already been deleted. After looking up the syntax for IF in DB2, I came up with this:
IF EXISTS (SELECT indname FROM SYSCAT.INDEXES WHERE INDNAME = 'TEST_CREATE_INDEX_OLD')
THEN
DROP INDEX TEST_CREATE_INDEX_OLD;
create index TEST_CREATE_INDEX_NEW on example_table
(
id,
another_field
);
END IF;
When run with either SQuirrel (already setup to run with db2) or via command line, this script results in an error:
An unexpected token "IF EXISTS (SELECT indname FROM SYSCAT.INDEX" was
found following "BEGIN-OF-STATEMENT". Expected tokens may include:
"".. SQLCODE=-104, SQLSTATE=42601, DRIVER=4.23.42 SQL Code:
-104, SQL State: 42601
So - what am I doing wrong? Am I missing something, or is there another way to achieve my goal (check for $thing in database, execute appropriate query) that so far has not occured to me?
If IF statement is valid only in a compound-SQL block (i.e. inside a stored-procedure/routine/function/anonymous-block).
It's not valid standalone as your question shows, and that is why Db2 throws the -104 error.
You can look up the explanation of the sqlcode -104 by looking up SQL0104N in the free online Db2 Knowledge Center at this link.
To be able to use compound-SQL in your Squirrel-SQL tool, you need to configure squirrel to use an alternative statement terminator. Google that. In the examples below, I show a statement terminator of # (to delimit the block).
Here are two different ways to do what you want with Db2-Linux/Unix/Windows, each uses an anonymous block. Other approaches are possible.
In this example the drop-index will only run if the index-name exists in the current schema:
begin
declare v_index_exists integer default 0;
select 1 into v_index_exists
from syscat.indexes
where indname = 'TEST_CREATE_INDEX_OLD';
if v_index_exists = 1
then
execute immediate('drop index TEST_CREATE_INDEX_OLD');
execute immediate('create index TEST_CREATE_INDEX_NEW on example_table ( id, another_field)');
end if;
end#
In this example the drop-index will always run, but the block won't abort if the index does'nt exist (i.e. it will continue and not throw any error).
begin
declare v_no_such_index integer default 0;
declare not_exists condition for sqlstate '42704';
declare continue handler for not_exists set v_no_such_index=1;
execute immediate('drop index TEST_CREATE_INDEX_OLD');
execute immediate('create index TEST_CREATE_INDEX_NEW on example_table ( id, another_field)');
end#
You must use another statement delimiter, if you want to use db2 compound statement.
In Squirrel: Session -> Session Properties -> SQL -> Statement Separator = #.
Indexes in Db2 are fully qualified by 2 SYSCAT.INDEXES columns: INDSCHEMA and INDNAME. So, it's advisable to use both these fields in a SELECT statement on SYSCAT.INDEXEX as in example.
You can't use static DDL statements in a compound statement. Use EXECUTE IMMEDIATE statements instead.
Below is an example emulating UPDATE INDEX for the index in a schema equal to CURRENT SCHEMA special registry set in the session.
BEGIN
IF EXISTS (SELECT indname FROM SYSCAT.INDEXES WHERE INDSCHEMA = CURRENT SCHEMA AND INDNAME = 'TEST_CREATE_INDEX_OLD')
THEN
EXECUTE IMMEDIATE 'DROP INDEX TEST_CREATE_INDEX_OLD';
EXECUTE IMMEDIATE'
create index TEST_CREATE_INDEX_NEW on example_table
(
id,
another_field
)
';
END IF;
END
#

Concatenate string in ALTER statement in REDSHIFT (syntax error)

I want alter an external table in redshift. If execute this query:
alter table "name_table"
set location 'a string' ||
TO_CHAR((getdate()-1)::date, 'YYYYMMDD') || '/';
give me a syntax error:
SQL Error [500310] [42601]: Amazon Invalid operation: syntax error at or near "||"
Position: 135;
Maybe I must use dynamic SQL but I'm not sure how do that. Can someone help me?
EDIT:
I try to use a procedure for alter an external table, this doesn't give me a syntax error but return an error like this:
You can't alter an external table with function or procedure.
Do you want update?
update "name_table"
set location = 'a string' || TO_CHAR((getdate()-1)::date, 'YYYYMMDD') || '/';
I don't think location can be dynamic. Though you issue this statement in SQL, you can't use standard operators to build the S3 path. It's the same limitation as in good old COPY TO statement (target file can't be dynamic).

Oracle error : ORA-00905: Missing keyword

Excuting the line of SQL:
SELECT *
INTO assignment_20081120
FROM assignment ;
against a database in oracle to back up a table called assignment gives me the following ORACLE error:
ORA-00905: Missing keyword
Unless there is a single row in the ASSIGNMENT table and ASSIGNMENT_20081120 is a local PL/SQL variable of type ASSIGNMENT%ROWTYPE, this is not what you want.
Assuming you are trying to create a new table and copy the existing data to that new table
CREATE TABLE assignment_20081120
AS
SELECT *
FROM assignment
First, I thought:
"...In Microsoft SQL Server the
SELECT...INTO automatically creates
the new table whereas Oracle seems to
require you to manually create it
before executing the SELECT...INTO
statement..."
But after manually generating a table, it still did not work, still showing the "missing keyword" error.
So I gave up this time and solved it by first manually creating the table, then using the "classic" SELECT statement:
INSERT INTO assignment_20081120 SELECT * FROM assignment;
Which worked as expected. If anyone come up with an explanaition on how to use the SELECT...INTO in a correct way, I would be happy!
You can use select into inside of a PLSQL block such as below.
Declare
l_variable assignment%rowtype
begin
select *
into l_variable
from assignment;
exception
when no_data_found then
dbms_output.put_line('No record avialable')
when too_many_rows then
dbms_output.put_line('Too many rows')
end;
This code will only work when there is exactly 1 row in assignment. Usually you will use this kind of code to select a specific row identified by a key number.
Declare
l_variable assignment%rowtype
begin
select *
into l_variable
from assignment
where ID=<my id number>;
exception
when no_data_found then
dbms_output.put_line('No record avialable')
when too_many_rows then
dbms_output.put_line('Too many rows')
end;
Though this is not directly related to the OP's exact question but I just found out that using a Oracle reserved word in your query (in my case the alias IN) can cause the same error.
Example:
SELECT * FROM TBL_INDEPENTS IN
JOIN TBL_VOTERS VO on IN.VOTERID = VO.VOTERID
Or if its in the query itself as a field name
SELECT ..., ...., IN, ..., .... FROM SOMETABLE
That would also throw that error. I hope this helps someone.
If you backup a table in Oracle Database. You try the statement below.
CREATE TABLE name_table_bk
AS
SELECT *
FROM name_table;
I am using Oracle Database 12c.
Late answer, but I just came on this list today!
CREATE TABLE assignment_20101120 AS SELECT * FROM assignment;
Does the same.