I wonder how read column names in oracle. Ok, I know that there is table named USER_TAB_COLUMNS which gives info about it, but if I have 2 or 3 level nested query and I don't know column names. Or I just have simple query with join statement and i want to get column names. How to do that? any idey?
select * from person a
join person_details b where a.person_id = b.person_id
thanks
I would go for:
select 'select ' || LISTAGG(column_name , ',') within group (order by column_id) || ' from T1'
from user_tab_columns
where table_name = 'T1';
to get a query from database. To get columns with types to fill map you can use just:
select column_name , data_type
from user_tab_columns
where table_name = 'T1';
I assume you are looking for this:
DECLARE
sqlStr VARCHAR2(1000);
cur INTEGER;
columnCount INTEGER;
describeColumns DBMS_SQL.DESC_TAB2;
BEGIN
sqlStr := 'SELECT a.*, b.*, SYSDATE as "Customized column name"
FROM person a JOIN person_details b
WHERE a.person_id = b.person_id';
cur := DBMS_SQL.OPEN_CURSOR;
DBMS_SQL.PARSE(cur, sqlStr, DBMS_SQL.NATIVE);
DBMS_SQL.DESCRIBE_COLUMNS2(cur, columnCount, describeColumns);
FOR i IN 1..columnCount LOOP
DBMS_OUTPUT.PUT_LINE ( describeColumns(i).COL_NAME );
END LOOP;
DBMS_SQL.CLOSE_CURSOR(cur);
END;
Related
I am working with a huge database with several columns and records. I want to browse a specific table and make a list of the columns that are empty for every record.
Is this possible without refering to all the specific column names?
Thanks for help!
It's possible but if you have a lot data it will last a long time.
create table xxx as select * from dba_objects where rownum < 10000;
prepare test table get table stats. It can be long lasting process.
begin
dbms_stats.gather_table_stats(user,'XXX',estimate_percent =>100);
-- ..
-- others tables to analizye
end;
Generate reports.
select table_name,column_name from user_tab_cols where coalesce(low_value,high_value) is null and table_name in('XXX');
You can use the below script to find out the null columns in your database -
DECLARE
COUNT_COL INT;
SQL_STR VARCHAR2(100);
BEGIN
FOR I IN (SELECT OBJECT_NAME, COLUMN_NAME
FROM USER_OBJECTS UO
JOIN USER_TAB_COLS UTC ON UO.OBJECT_NAME = UTC.TABLE_NAME) LOOP
SQL_STR := 'SELECT COUNT(1) FROM ' || I.OBJECT_NAME || ' WHERE ' || i.COLUMN_NAME || ' IS NOT NULL';
EXECUTE IMMEDIATE SQL_STR INTO COUNT_COL;
IF COUNT_COL = 0 THEN
DBMS_OUTPUT.PUT_LINE(I.COLUMN_NAME);
END IF;
END LOOP;
END;
Here is the fiddle.
Try for all record in table:
SELECT a.owner, a.table_name, b.column_name
FROM all_tables a, all_tab_columns b
WHERE a.table_name = '<TABLE_NAME>'
AND a.table_name = b.table_name
AND a.num_rows = b.num_nulls
For all table
SELECT a.owner, a.table_name, b.column_name
FROM all_tables a, all_tab_columns b
WHERE a.table_name = b.table_name
AND a.num_rows = b.num_nulls
I write one dynamic SQL which the result of it is a table with 2 columns and multiple rows, I want to insert it to another table with 4 columns that 2 of them will be filled by the result of dynamic SQL, I try to use collection but don't know how to insert result to another table
CREATE OR REPLACE PROCEDURE P_C_SM_Failure_error_Code_P2P AS
v_month VARCHAR2(16); -- to get Month for each table
v_day VARCHAR2(16); -- to get day for each table
v_ERRCODE t_c_rpt_resultmsg.code%TYPE;
v_ERRMSG t_c_rpt_resultmsg.MESSAGE%TYPE;
v_param VARCHAR2(16);
v_sql VARCHAR2(3000);
v_result number;
type t_c_result is record (Err_code varchar2(2000), Err_count number);
type v_t_result is table of t_c_result index by PLS_INTEGER;
v_t1_result v_t_result;
BEGIN
v_sql :='0';
v_param := 'Gateway_G';
v_result := '0';
select to_char(sysdate - 1,'MM') into v_month from dual;
select to_char(sysdate - 1,'DD') into v_day from dual;
-- Get count of P2P
v_sql := '(select count(*), error_code from (
select error_code from sm_histable'||v_month||''||v_day||'#ORASMSC01 where
orgaccount = '''||v_param||''' and destaccount = '''||v_param||''' and
sm_status <> 1 union all
select error_code from sm_histable'||v_month||''||v_day||'#ORASMSC02 where
orgaccount = '''||v_param||''' and destaccount = '''||v_param||''' and
sm_status <> 1 )
group by error_code)';
EXECUTE IMMEDIATE v_sql bulk collect into v_t1_result;
--insert into t_c_rpt_result2 values (trunc(sysdate, 'DD'), v_errcount,
v_err_code,'Failure_error_Code_P2P');
--for indx in 1 .. v_t1_result.COUNT
--loop
--dbms_output.put_line (v_t1_result (indx).Err_code);
--end loop;
You may append the constant values of date and the error message to the subquery and run a dynamic insert. It should also work if you remove the outer parentheses of your dynamic sql since constants can be included in group by. Always remember to pass values as bind variables rather than concatenating them (v_param). Also, specify the column names explicitly in an INSERT statement.
v_sql := '(select count(*) as cnt, error_code
from (
select error_code from sm_histable'||v_month||''||v_day||'#ORASMSC01
where orgaccount = :x and destaccount = :x and sm_status <> 1
union all
select error_code from sm_histable'||v_month||''||v_day||'#ORASMSC02
where orgaccount = :x and destaccount = :x and sm_status <> 1 )
group by error_code)';
EXECUTE IMMEDIATE v_sql bulk collect into v_t1_result using v_param;
EXECUTE IMMEDIATE 'insert into t_c_rpt_result2(err_dt,err_msg,errcount,error_code)
select :dt,:msg,cnt,error_code from '|| v_sql
USING trunc(sysdate, 'DD'),'Failure_error_Code_P2P',v_param;
I think you are looking at an excellent use case for FORALL. The collection you are populating needs to be done with execute immediate since you are dynamically constructing the table name. But the insert into t_c_rpt_result2 looks static to me.
BEGIN
v_sql :=
'(select count(*) as cnt, error_code
from (
select error_code from sm_histable'
|| v_month
|| ''
|| v_day
|| '#ORASMSC01
where orgaccount = :x and destaccount = :x and sm_status <> 1
union all
select error_code from sm_histable'
|| v_month
|| ''
|| v_day
|| '#ORASMSC02
where orgaccount = :x and destaccount = :x and sm_status <> 1 )
group by error_code)';
EXECUTE IMMEDIATE v_sql BULK COLLECT INTO v_t1_result USING v_param;
FORALL indx IN 1 .. v_t1_result.COUNT
INSERT INTO t_c_rpt_result2 (err_dt,
err_msg,
errcount,
ERROR_CODE)
VALUES (TRUNC (SYSDATE, 'DD'),
'Failure_error_Code_P2P',
v_t1_result (indx).cnt,
v_t1_result (indx).ERROR_CODE);
END;
Find more examples of FORALL on LiveSQL here. Of course, even if your insert was dynamic, you can use FORALL - put the execute immediate directly "inside" the FORALL statement. But I don't think that complexity is justified here.
Hope that helps!
I have the following block of PL-SQL code in Oracle:
DECLARE TAB VARCHAR(100);
COL VARCHAR(100);
CURSOR C_COLS IS
select DISTINCT table_name, column_name
from all_tab_columns
where OWNER = 'MyDB' AND DATA_TYPE LIKE '%VARCHAR%';
BEGIN
OPEN C_COLS;
LOOP
FETCH C_COLS INTO TAB, COL;
EXIT WHEN C_COLS%notfound;
INSERT INTO TargetTable (TABLE_NAME, COLUMN_NAME, COLUMN_VALUE)
SELECT DISTINCT TAB,
COL,
(SELECT COL FROM TAB)
FROM TAB
WHERE REGEXP_LIKE(COL, '([ABCDEFGHIJKLMNOPQRSTUVWXYZ])\d\d\d\d\d\d([ABCDEFGHIJKLMNOPQRSTUVWXYZ])', 'ix');
END LOOP;
CLOSE C_COLS;
END;
The idea is to determine which tables in my rather large database contain a certain pattern of data and to find them.
So I want to return three columns: TableName, ColumnName, Value of ColumnName.
The above runs but returns no data and I can't understand why. The query in the cursor returns results, and if I hard code the table values into a simple select statement containing my Regex, I get results. I just want one result set that contains the thousands of results I expect.
Could it be the (SELECT COL FROM TAB) I'm using to dynamically find the column_value? I wasn't sure if I could express it this way.
If you want to select columns dynamically you may wish to try dynamic SQL.
DECLARE
w_sql VARCHAR2(32767);
BEGIN
DBMS_OUTPUT.enable(32767);
FOR s_cols IN (
select DISTINCT
table_name
, column_name
from all_tab_columns
where owner = 'MyDB'
AND data_type LIKE '%VARCHAR%'
)
LOOP
w_sql := q'!
INSERT
INTO TargetTable (TABLE_NAME, COLUMN_NAME, COLUMN_VALUE)
SELECT DISTINCT
':TAB'
, ':COL'
, :COL
FROM :TAB
WHERE REGEXP_LIKE(:COL, '([ABCDEFGHIJKLMNOPQRSTUVWXYZ])\d\d\d\d\d\d([ABCDEFGHIJKLMNOPQRSTUVWXYZ])', 'ix')
!';
w_sql := REPLACE(w_sql, ':TAB', s_cols.table_name);
w_sql := REPLACE(w_sql, ':COL', s_cols.column_name);
EXECUTE IMMEDIATE w_sql;
END LOOP;
COMMIT;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.put_line('Error for SQL :'|| w_sql ||'; error is :'|| SQLERRM);
END;
Below is a PL/SQL I'm working on
declare
v_sql varchar2(500);
BEGIN
for t in (
SELECT distinct ID
FROM TABLEB
) loop
for c in (
select * from (
select 'delete from ' as test
from dual
union all
select 'TABLEA'||' where ' as test
from dual
union all
select 'ID='||t.ID
from dual
)
) loop
v_sql := v_sql || c.test;
end loop;
dbms_output.put_line(v_sql);
end loop;
END;
/
The result I'm getting is this
delete from TABLEA where ID=1
delete from TABLEA where ID=1delete from TABLEA where ID=2
I want
delete from TABLEA where ID=1
delete from TABLEA where ID=2
Any help on the PLSQL will be appreciated
What is the purpose of the inner FOR loop? It does nothing that requires a loop, and can be simply rewritten like this:
declare
v_sql varchar2(500);
begin
for t in (select distinct id from tableb) loop
v_sql := 'delete from tablea where id = ' || t.id ||';';
dbms_output.put_line(v_sql);
end loop;
end;
/
BTW, it seems that you're missing the terminating semicolon in line v_sql := ...
Demonstration on HR's DEPARTMENTS table:
SQL> declare
2 v_sql varchar2(500);
3 begin
4 for t in (select distinct department_id id from departments) loop
5 v_sql := 'delete from tablea where id = ' || t.id ||';';
6 dbms_output.put_line(v_sql);
7 end loop;
8 end;
9 /
delete from tablea where id = 10;
delete from tablea where id = 20;
delete from tablea where id = 30;
delete from tablea where id = 40;
delete from tablea where id = 50;
delete from tablea where id = 60;
<snip>
You're not clearing the buffer after you've printed the statement, so you're appending the next statement to the first one. To clear the buffer, add
v_sql := NULL;
after the line which reads
dbms_output.put_line(v_sql);
Best of luck.
I have loop for all the tables into db:
declare
V_TABL_NM ALL_TABLES.TABLE_NAME%TYPE;
BEGIN
FOR GET_TABL_LIST IN (SELECT TABLE_NAME FROM ALL_TABLES )LOOP
V_TABL_NM := GET_TABL_LIST.TABLE_NAME;
DBMS_OUTPUT.PUT_LINE(V_TABL_NM);
END LOOP;
END;
How can I sort my result and add number of records for each tables?
I try below but it does not work:
declare
V_TABL_NM ALL_TABLES.TABLE_NAME%TYPE;
table_row number;
BEGIN
FOR GET_TABL_LIST IN (SELECT TABLE_NAME FROM ALL_TABLES )LOOP
V_TABL_NM := GET_TABL_LIST.TABLE_NAME;
table_row: = select count(*) from TABLE_NAME;
DBMS_OUTPUT.PUT_LINE(V_TABL_NM, table_row);
END LOOP;
END;
You can not make a query that way; TABLE_NAME has no meaning there (and you're missing to use the cursor name), so you need to build a dynamic SQL and run it to put the value into a variable.
Besides, the PUT_LINE does not accept that parameters.
This should work:
DECLARE
table_row NUMBER;
BEGIN
FOR GET_TABL_LIST IN ( SELECT OWNER || '.' || TABLE_NAME AS TABLE_NAME
FROM ALL_TABLES
ORDER BY TABLE_NAME)
LOOP
EXECUTE IMMEDIATE 'select count(*) from ' || GET_TABL_LIST.TABLE_NAME INTO table_row;
DBMS_OUTPUT.PUT_LINE(GET_TABL_LIST.TABLE_NAME || ' - ' || table_row);
END LOOP;
END;
About the ordering, simply add an ORDER BY to the query looping through the tables
This assumes that you have rights to query all the tables listed in ALL_TABLES If you simply need to query all the tables of your schema, use USER_TABLES instead of ALL_TABLES.
to sort the results add order by clausel:
FOR GET_TABL_LIST IN
(
SELECT TABLE_NAME
FROM ALL_TABLES
ORDER BY TABLE_NAME --
)LOOP
to count the records use dynamic sql :
execute immediate 'select count(*) from ' || V_TABL_NM INTO table_row;
This can be done completely without PL/SQL:
select table_name,
to_number(extractvalue(xmltype(dbms_xmlgen.getxml('select count(*) c from '||table_name)),'/ROWSET/ROW/C')) as rowcount
from user_tables
order by rowcount;
also I did:
select TABLE_NAME, NUM_ROWS, LAST_ANALYZED
from user_tables
order by 1;