I know that I can comment a column with COMMENT ON COLUMN table.column IS 'commentString', but is there a way to add the same comment to more than one column in one statement?
For example, I need to add the comment "User Data" to columns NAME and BIRTHDATE and I'd like to understand if it's possible to do it in one statement, instead of repeating COMMENT ON COLUMN x.y IS 'User Data' two times.
It is impossible in straight way, but you can do it with dynamic SQL in PL\SQL block
BEGIN
FOR i IN (SELECT t.owner || '.' || t.table_name || '.' || t.column_name col
FROM all_tab_cols t
WHERE t.owner = 'OWNER' AND t.table_name = 'TABLE_NAME' AND
t.column_name IN ('COL1', 'COL2'))
LOOP
EXECUTE IMMEDIATE 'COMMENT ON COLUMN ' || i.col ||
' IS ''PLACE COMMENT HERE''';
END LOOP;
END;
Related
I have a table on snowflake which has more than 100 columns, and I would like to add a suffix '_LA' to all the column names. Is there any easy way to do this in sql?
this script produce alter command for all columns of given schema.table name:
select 'ALTER TABLE ' || table_schema || '.' || table_name || ' RENAME COLUMN ' || column_name || ' TO _LA' || column_name
from information_schema.columns
where table_schema ilike 'schema' -- put your schema name here
and table_name ilike 'table' -- put your table name here
order by ordinal_position;
I'm going mental over this. I'm fairly new to dynamic SQL, so I may just not be asking Google the right question, but here's what I'm trying to do... I have a query with dynamic SQL. When I run that query, it produces several rows. All of these rows (about 30) make up a single union query. I can copy all of those rows and paste into a new query and run - works fine, but what I need to do is run this all in a single query. I've looked up examples of using execute immediate and fetch, but I cannot seem to get them to actually spit out the data...they just end up saying something like "Executed Successfully", but doesn't actually produce any resulting rows. The resulting column name of the below SQL is "qry_txt" - instead of producing it at face value, I want to execute it as a query. Again, I may not be articulating this well, but I'm basically trying to turn 2 queries (with a manual copy/paste step involved) into a single query. Hope this makes sense...
Here's my SQL:
Select CASE when
lead(ROWNUM) over(order by ROWNUM) is null then
'SELECT '||''''||T.TABLE_NAME||''''||' as TABLE_NAME,'||''''||T.COLUMN_NAME||''''||' as COLUMN_NAME, cast('|| T.COLUMN_NAME ||' as
varchar2(100)) as SAMPLE_DATA ||
from rpt.'||T.TABLE_NAME ||' where '||T.COLUMN_NAME||' is not null and ROWNUM=1;'
else
'SELECT '||''''||T.TABLE_NAME||''''||' as TABLE_NAME,'||''''||T.COLUMN_NAME||''''||' as COLUMN_NAME, cast('|| T.COLUMN_NAME ||' as
varchar2(100)) as SAMPLE_DATA from rpt.'||T.TABLE_NAME ||' where '||T.COLUMN_NAME||' is not null and ROWNUM=1 union ' end as qry_txt
from all_tab_columns t where T.OWNER='rpt' and T.DATA_TYPE != 'BLOB' and T.DATA_TYPE != 'LONG' and T.TABLE_NAME = 'NME_DMN'
ORDER BY ROWNUM asc;
You cannot write a dynamic query in a SQL. You need to use PLSQL block to accomploish that. Please see how you can do it.
PS: Code is not tested.
declare
var1 <decalration same of column in select list> ;
var2 <decalration same of column in select list> ;
var3 <decalration same of column in select list> ;
....
varn ;
begin
for i in ( SELECT LEAD (ROWNUM) OVER (ORDER BY ROWNUM) COl1
FROM all_tab_columns t
WHERE T.OWNER = 'rpt'
AND T.DATA_TYPE != 'BLOB'
AND T.DATA_TYPE != 'LONG'
AND T.TABLE_NAME = 'NME_DMN'
ORDER BY ROWNUM ASC)
Loop
If i.col1 IS NULL Then
execute immediate 'SELECT '
|| ''''
|| T.TABLE_NAME
|| ''''
|| ' as TABLE_NAME,'
|| ''''
|| T.COLUMN_NAME
|| ''''
|| ' as COLUMN_NAME, cast('
|| T.COLUMN_NAME
|| ' as
varchar2(100)) as SAMPLE_DATA ||
from rpt.'
|| T.TABLE_NAME
|| ' where '
|| T.COLUMN_NAME
|| ' is not null and ROWNUM=1' into var1 , var2 ,var3 ....varn;
Else
execute immediate 'SELECT '
|| ''''
|| T.TABLE_NAME
|| ''''
|| ' as TABLE_NAME,'
|| ''''
|| T.COLUMN_NAME
|| ''''
|| ' as COLUMN_NAME, cast('
|| T.COLUMN_NAME
|| ' as
varchar2(100)) as SAMPLE_DATA from rpt.'
|| T.TABLE_NAME
|| ' where '
|| T.COLUMN_NAME
|| ' is not null and ROWNUM=1' into var1 , var2 ,var3 ....varn;
end if;
End Loop;
exception
when others then
dbms_output.put_lin(sqlcode ||'--'||sqlerrm);
End;
I need to update a column matching a specific pattern in all tables in an oracle database.
For example I have in all tables this column *_CID with is a foreign key to master table witch has a primary key CID
Thanks
You can use the naming convention and query all_tab_columns
declare
cursor c is
select table_owner , column_name, table_name from all_tab_columns where column_name like '%_CID';
begin
for x in c loop
execute immediate 'update ' || x.table_owner || '.' || x.table_name ||' set ' || x.column_name||' = 0';
end loop;
end;
If you have valid Fk's you can also use all_tab_constraints the fetch enabled FK's for your main table and fetch the columns name of the r_constraint_name.
I found a solution to my question:
BEGIN
FOR x IN (SELECT owner, table_name, column_name FROM all_tab_columns) LOOP
EXECUTE IMMEDIATE 'update ' || x.owner || '.' || x.table_name ||' set ' || x.column_name||' = 0 where '||x.column_name||' = 1';
END LOOP;
END;
thanks
I know this question may ask many times but I could not find one line SQL statement.
I remember I did it before but now I could not remember how I did
I want to drop all tables whose name starts with "EXT_". Is it possibile to make it happen with one line SQL statement.
You could use a short anonymous block to do this.
BEGIN
FOR c IN ( SELECT table_name FROM user_tables WHERE table_name LIKE 'EXT_%' )
LOOP
EXECUTE IMMEDIATE 'DROP TABLE ' || c.table_name;
END LOOP;
END;
It's not possible with only one statement. Usually, I write a sql to get all the tables and then execute the results:
select 'drop table ' || table_name || ';'
from user_tables
where table_name like 'EXT_%';
This code will DROP not only EXT_% tables, it will act as DROP EXT% also.
Underscore is as special wildcard that acts as '%' but for a single character.
BEGIN
FOR c IN ( SELECT table_name FROM user_tables WHERE table_name LIKE 'EXT_%' )
LOOP
EXECUTE IMMEDIATE 'DROP TABLE ' || c.table_name;
END LOOP;
END;
In order to achieved desired results you should change your code the way below
BEGIN
FOR c IN ( SELECT table_name FROM user_tables WHERE table_name LIKE 'EXT\_%' ESCAPE '\')
LOOP
EXECUTE IMMEDIATE 'DROP TABLE ' || c.table_name;
END LOOP;
END;
It escapes underscore char in order to be trated literally, ESCAPE '\' modifier indicates that escape char is '\'
In most of cases you will find contraints violations. In that case, this script can help you:
DECLARE
c_action CONSTANT VARCHAR2(10) := 'DROP';
BEGIN
FOR c IN ( SELECT table_name FROM user_tables WHERE table_name LIKE 'STARTINGTEXT_%' )
LOOP
FOR reg IN (SELECT uc.table_name,
uc.constraint_name
FROM user_constraints uc
WHERE uc.table_name IN (c.table_name)) LOOP
EXECUTE IMMEDIATE 'ALTER TABLE ' || reg.table_name || ' ' || c_action ||
' CONSTRAINT ' || reg.constraint_name ;
END LOOP;
END LOOP;
COMMIT;
FOR c IN ( SELECT table_name FROM user_tables WHERE table_name LIKE 'STARTINGTEXT_%' )
LOOP
EXECUTE IMMEDIATE 'TRUNCATE TABLE ' || c.table_name;
EXECUTE IMMEDIATE 'DROP TABLE ' || c.table_name;
END LOOP;
END;
I need to run a query on generated generated column names.
Here's the query:
select 'col_'||4 from MY_TABLE
Note:
"4" is a variable that is passed to this query from within the Java code
MY_TABLE is a table that contain columns with names (col_4, col_5, etc..)
Inside Oracle you need use dynamic SQL. (YourVariable value is 4 for your example)
EXECUTE IMMEDIATE ' select col_' || YourVariable || ' from MY_TABLE ';
From Java you can build any SQL and execute them
To run a dynamic SELECT statement, you have two choices:
For single row selects, you use EXECUTE IMMEDIATE ... INTO:
EXECUTE IMMEDIATE 'select col_' || l_num || ' from MY_TABLE WHERE id = 37' INTO l_result;
For selecting multiple rows, you can use a dynamic cursor:
DECLARE
TYPE MyCurType IS REF CURSOR;
my_cv MyCurType;
BEGIN
OPEN emp_cv FOR 'select col_' || l_num || ' from MY_TABLE';
...
END;
This code generates a SELECT that returns the tables with their column name:
SELECT
'SELECT ' ||(
SELECT
LISTAGG(
c.TABLE_NAME || '.' || c.COLUMN_NAME || ' AS "' || c.TABLE_NAME || '.' || c.COLUMN_NAME || '"',
', '
) WITHIN GROUP(
ORDER BY
c.TABLE_NAME
) "TABLE_NAMES"
FROM
USER_TAB_COLS c
WHERE
TABLE_NAME IN(
'PESSOA',
'PESSOA_FISICA',
'PESSOA_JURIDICA'
)
)|| 'FROM PERSON;'
FROM
DUAL;