I need remove the quotes from the names of the columns in many tables in my schema. there is any way to automate this process?, any function in oracle or some tool that allows me to change the names of the columns removing the quotes. I am using oracle 11g.
UPDATE
I'm sorry, I had to rephrase my question.
thanks in advance.
I assume here by "fields" you mean "column names".
Keep in mind that column names in Oracle are not case sensitive unless you put them in quotes when creating the table. It's generally not a good idea to use quotes around the column names when creating the table. In other words, if you create the table like this:
CREATE TABLE FOO (
colUMN1 varchar2(10),
CoLumn2 number(38)
)
Then you can still run select statements like this:
SELECT column1, column2 FROM FOO
You can also do this:
SELECT COLUMN1, COLUMN2 FROM FOO
Also note that if you run this query, you'll see that Oracle stored the column names as uppercase in the data dictionary:
SELECT * FROM ALL_TAB_COLUMNS WHERE TABLE_NAME = 'FOO'
So there's no need to rename these columns to all uppercase. The queries you write can use all uppercase column names (assuming the tables weren't created using quotes around the column names) and they'll work fine. It's generally a bad idea to try to force them to be case sensitive.
If you just want to get rid of all the case sensitive column names
SQL> create table foo ( "x" number );
Table created.
SQL> ed
Wrote file afiedt.buf
1 begin
2 for x in (select *
3 from user_tab_cols
4 where column_name != UPPER(column_name))
5 loop
6 execute immediate 'ALTER TABLE ' || x.table_name ||
7 ' RENAME column "' || x.column_name || '"' ||
8 ' TO ' || upper(x.column_name);
9 end loop;
10* end;
SQL> /
PL/SQL procedure successfully completed.
SQL> desc foo
Name Null? Type
----------------------------------------- -------- ----------------------------
X NUMBER
Related
Assume following table named t1:
create table t1(
clid number,
A number,
B number,
C number
)
insert into t1 values(1, 1, 1, 1);
insert into t1 values(2, 0, 1, 0);
insert into t1 values(3, 1, 0, 1);
clid A B C
1 1 1 1
2 0 1 0
3 1 0 1
Type of columns A, B, and C is number. What I need to do is to change types of those columns to VARCHAR but in a quite tricky way.
In my real table I need to change datatype for hundred of columns so it is not so convenient to write a statement like following hundred of time:
ALTER TABLE table_name
MODIFY column_name datatype;
What i need to do is rather to convert all columns to VARCHAR except CLID column like we can do that in Python or R
Is there any way to do so in Oracle SQL or PLSQL?
Appreciate your help.
Here is a example of procedure that can help...
It accepts two parameters that should be a name of your table and list of columns you do not want to change...
At the begining there is a cursor that gets all the column names for your table except the one that you do not want to change...
Then it loop's though the columns and changes them...
CREATE OR REPLACE procedure test_proc(p_tab_name in varchar2
, p_col_names in varchar2)
IS
v_string varchar2(4000);
cursor c_tab_cols
is
SELECT column_name
FROM ALL_TAB_COLS
WHERE table_name = upper(p_tab_name)
and column_name not in (select regexp_substr(p_col_names,'[^,]+', 1, level) from dual
connect by regexp_substr(p_col_names, '[^,]+', 1, level) is not null);
begin
FOR i_record IN c_tab_cols
loop
v_string := 'alter table ' || p_tab_name || ' modify '
|| i_record.column_name || ' varchar(30)';
EXECUTE IMMEDIATE v_string;
end loop;
end;
/
Here is a demo:
DEMO
You can also extend this procedure with a type of data you want to change into... and with some more options I am sure....
Unfortunately, that isn't as simple as you'd want it to be. It is not a problem to write query which will write query for you (by querying USER_TAB_COLUMNS), but - column must be empty in order to change its datatype:
SQL> create table t1 (a number);
Table created.
SQL> insert into t1 values (1);
1 row created.
SQL> alter table t1 modify a varchar2(1);
alter table t1 modify a varchar2(1)
*
ERROR at line 1:
ORA-01439: column to be modified must be empty to change datatype
SQL>
If there are hundreds of columns involved, maybe you can't even
create additional columns in the same table (of VARCHAR2 datatype)
move values in there
drop "original" columns
rename "new" columns to "old names"
because there'a limit of 1000 columns per table.
Therefore,
creating a new table (with appropriate columns' datatypes),
moving data over there,
dropping the "original" table
renaming the "new" table to "old name"
is probably what you'll finally do. Note that it won't be necessarily easy either, especially if there are foreign keys involved.
A "query that writes query for you" might look like this (Scott's sample tables):
SQL> SELECT 'insert into dept (deptno, dname, loc) '
2 || 'select '
3 || LISTAGG ('to_char(' || column_name || ')', ', ')
4 WITHIN GROUP (ORDER BY column_name)
5 || ' from emp'
6 FROM user_tab_columns
7 WHERE table_name = 'EMP'
8 AND COLUMN_ID <= 3
9 /
insert into dept (deptno, dname, loc) select to_char(EMPNO), to_char(ENAME), to_char(JOB) from emp
SQL>
It'll save you from typing names of hundreds of columns.
I think its not possible to change data type of a column if values are there...
Empty the column by copying values to a dummy column and change data types.
I like to find all columns in my Oracle database schema that only contain numeric data but having a non-numeric type. (So basically column-candidates with probably wrong chosen data types.)
I have a query for all varchar2-columns:
SELECT TABLE_NAME, COLUMN_NAME, DATA_TYPE
FROM user_tab_cols
WHERE DATA_TYPE = 'VARCHAR2';
Furthermore I have a query to check for any non-numeric data inside a table myTable and a column myColumn:
SELECT 1
FROM myTable
WHERE NOT REGEXP_LIKE(myColumn, '^[[:digit:]]+$');
I like to combine both queries in that way that the first query only returns the rows where not exists the second.
The main problem here is that the first query is on meta layer of the data dictionary where TABLE_NAME and COLUMN_NAME comes as data and I need that data as identifiers (and not as data) in the second query.
In pseudo-SQL I have something like that in mind:
SELECT TABLE_NAME, COLUMN_NAME, DATA_TYPE
FROM user_tab_cols
WHERE DATA_TYPE = 'VARCHAR2'
AND NOT EXISTS
(SELECT 1 from asIdentifier(TABLE_NAME)
WHERE NOT REGEXP_LIKE(asIdentifier(COLUMN_NAME), '^[[:digit:]]+$'));
Create a function as this:
create or replace function isNumeric(val in VARCHAR2) return INTEGER AS
res NUMBER;
begin
res := TO_NUMBER(val);
RETURN 1;
EXCEPTION
WHEN OTHERS THEN
RETURN 0;
END;
Then you can use it like this:
DECLARE
r integer;
BEGIN
For aCol in (SELECT TABLE_NAME, COLUMN_NAME FROM user_tab_cols WHERE DATA_TYPE = 'VARCHAR2') LOOP
-- What about CHAR and CLOB data types?
execute immediate 'select count(*) from '||aCol.TABLE_NAME||' WHERE isNumeric('||aCol.COLUMN_NAME||') = 0' into r;
if r = 0 then
DBMS_OUTPUT.put_line(aCol.TABLE_NAME ||' '||aCol.COLUMN_NAME ||' contains numeric values only');
end if;
end loop;
end;
Note, the performance of this PL/SQL block will be poor. Hopefully this is a one-time-job only.
There are two possible approaches: dynamic SQL (DSQL) and XML.
First one was already demonstrated in another reply and it's faster.
XML approach just for fun
create or replace function to_number_udf(p in varchar2) return number
deterministic is
pragma udf;
begin
return p * 0;
exception when invalid_number or value_error then return 1;
end to_number_udf;
/
create table t_chk(str1, str2) as
select '1', '2' from dual union all
select '0001.1000', 'helloworld' from dual;
SQL> column owner format a20
SQL> column table_name format a20
SQL> column column_name format a20
SQL> with tabs_to_check as
2 (
3 select 'collection("oradb:/'||owner||'/'||table_name||'")/ROW/'||column_name||'/text()' x,
4 atc.*
5 from all_tab_columns atc
6 where table_name = 'T_CHK'
7 and data_type = 'VARCHAR2'
8 and owner = user
9 )
10 select --+ no_query_transformation
11 owner, table_name, column_name
12 from tabs_to_check ttc, xmltable(x columns "." varchar2(4000)) x
13 group by owner, table_name, column_name
14 having max(to_number_udf(".")) = 0;
OWNER TABLE_NAME COLUMN_NAME
-------------------- -------------------- --------------------
TEST T_CHK STR1
PS. On Oracle 12.2 you can use to_number(... default ... on conversion error) instead of UDF.
The faster way to check if a string is all digits vs. contains at least one non-digit character is to use the translate function. Alas, due to the non-SQL Standard way Oracle handles empty strings, the form of the function we must use is a little complicated:
translate(input_string, 'z0123456789', 'z')
(z can be any non-digit character; we need it so that the third argument is not null). This works by translating z to itself and 0, etc. to nothing. So if the input string was null or all-digits, and ONLY in that case, the value returned by the function is null.
In addition: to make the process faster, you can test each column with an EXISTS condition. If a column is not meant to be numeric, then in most cases the EXISTS condition will become true very quickly, so you will have to inspect a very small number of values from such columns.
As I tried to make this work, I ran into numerous side issues. Presumably you want to look in all schemas (except SYS and perhaps SYSTEM). So you need to run the procedure (anonymous block) from an account with SYSDBA privileges. Then - I ran into issues with non-standard table and column names (names starting with an underscore and such); which brought to mind identifiers defined in double-quotes - a terrible practice.
For illustration, I will use the HR schema - on which the approach worked. You may need to tweak this further; I wasn't able to make it work by changing the line
and owner = 'HR'
to
and owner != 'SYS'
So - with this long intro - here is what I did.
First, in a "normal" user account (my own, named INTRO - I run a very small database, with only one "normal" user, plus the Oracle "standard" users like SCOTT, HR etc.) - so, in schema INTRO, I created a table to receive the owner name, table name and column name for all columns of data type VARCHAR2 and which contain only "numeric" values or null (numeric defined the way you did.) NOTE HERE: If you then want to really check for all numeric values, you will indeed need a regular expression, or something like what Wernfried has shown; I would still, otherwise, use an EXISTS condition rather than a COUNT in the anonymous procedure.
Then I created an anonymous block to find the needed columns. NOTE: You will not have a schema INTRO - so change it everywhere in my code (both in creating the table and in the anonymous block). If the procedure completes successfully, you should be able to query the table. I show that at the end too.
While logged in as SYS (or another user with SYSDBA powers):
create table intro.cols_with_numbers (
owner_name varchar2(128),
table_name varchar2(128),
column_name varchar2(128)
);
declare x number;
begin
execute immediate 'truncate table intro.cols_with_numbers';
for t in ( select owner, table_name, column_name
from dba_tab_columns
where data_type like 'VARCHAR2%'
and owner = 'HR'
)
loop
execute immediate 'select case when exists (
select *
from ' || t.owner || '.' || t.table_name ||
' where translate(' || t.column_name || ',
''z0123456789'', ''z'') is not null
) then 1 end
from dual'
into x;
if x is null then
insert into intro.cols_with_numbers (owner_name, table_name, column_name)
values(t.owner, t.table_name, t.column_name);
end if;
end loop;
end;
/
Run this procedure and then query the table:
select * from intro.cols_with_numbers;
no rows selected
(which means there were no numeric columns in tables in the HR schema, in the wrong data type VARCHAR2 - or at least, no such columns that had only non-negative integer values.) You can test further, by intentionally creating a table with such a column and testing to see it is "caught" by the procedure.
ADDED - Here is what happens when I change the owner from 'HR' to 'SCOTT':
PL/SQL procedure successfully completed.
OWNER_NAME TABLE_NAME COLUMN_NAME
-------------------- -------------------- --------------------
SCOTT BONUS JOB
SCOTT BONUS ENAME
so it seems to work fine (although on other schemas I sometimes run into an error... I'll see if I can figure out what that is).
In this case the table is empty (no rows!) - this is one example of a "false positive" you may find. (More generally, you will get a false positive if everything in a VARCHAR2 column is null - in all rows of the table.)
NOTE also that a column may have only numeric values and still the best data type would be VARCHAR2. This is the case when the values are simply identifiers and are not meant as "numbers" (which we can compare to each other or to fixed values, and/or with which we can do arithmetic). Example - a SSN (Social Security Number) or the equivalent in other countries; the SSN is each person's "official" identifier for doing business with the government. The SSN is numeric (actually, perhaps to accentuate the fact it is NOT supposed to be a "number" despite the name, it is often written with a couple of dashes...)
I have 3 textfields where user types table name and 2 column names which need to be merged.
How should I merge (combine) 2 column values into 1?
I use oracle 11g enterprise
concatenate?
select col1 || ' ' || col2 from tablex
This is a very vague requirement. Concatenate the values maybe?
insert into sometable( Column1 )
values ( Column1 || Column2 );
If you need to specify the table name to INSERT into, then you will need to use dynamic SQL to achieve this. Would you need to specify the target column name as well? This example assumes you would use PL/SQL, which may not be appropriate in your case.
sql_stmt := 'INSERT INTO '|| specified_table || '(' || merge_column || ') VALUES ( :1 )';
EXECUTE IMMEDIATE sql_stmt USING column1 || column2;
http://docs.oracle.com/cd/B13789_01/appdev.101/b10807/13_elems017.htm
You could make another column (an auxiliary column ) and replace the other 2 columns with this one.
Merging columns in Oracle Live
SELECT CONCAT (ENAME, JOB) from scott.EMP
the above command will merge ENAME and JOB columns, and these 2 different columns will be shown in a single column
I have a problem in that I want my output to be a single table (lets call it Output) with 2 columns: one for the "TableName" and one for the DateTime of the last update (using the scn_to_timestamp(max(ora_rowscn)) command).
I have 100 tables and I want to pull in the last update date/times for all these tables into the Output table.
So I can do this:
insert into Output(TableName)
select table_name
from all_tables;
which will put all the tables I have from my database into the TableName column. But I don't know how to loop through each entry and use the tablename as a variable and pass this into the scn_to_timestamp(ora_rowscn).
I thought I would try something like below:
for counter in Output(TableName) LOOP
insert into Output(UpdateDate)
select scn_to_timestamp(max(ora_rowscn))
from counter;
END LOOP;
Any suggestions?
Thank you
This query is a little bit clumsy as it uses xmlgen to execute dynamic sql in a query, but it might work for you.
select x.*
from all_tables t,
xmltable('/ROWSET/ROW' passing
dbms_xmlgen.getxmltype('select ''' || t.table_name ||
''' tab_name, max(ora_rowscn) as la from ' ||
t.table_name)
COLUMNS tab_name varchar2(30) PATH 'TAB_NAME',
max_scn number PATH 'LA') x
Here is a sqlfiddle demo
You can also use PLSQL and then use execute immediate
Hi everyone what I'm wondering if I can do is create a table that lists the record counts of other tables. It would get those table names from a table. So let's assume I have the table TABLE_LIST that looks like this
name
---------
sports_products <-- contains 10 records
house_products <-- contains 8 records
beauty_products <-- contains 15 records
I would like to write a statement that pulls the names from those tables to query them and coount the records and ultimately produce this table
name numRecords
------------------------------
sports_products 10
house_products 8
beauty_products 15
So I think I would need to do something like this pseudo code
select *
from foreach tableName in select name from table_list
select count(*) as numRecords
from tableName
loop
You can have a function that is doing this for you via dynamic sql.
However, make sure to declare it as authid current_user. You do not want anyone to gain some sort of privilege elevation by exploiting your function.
create or replace function SampleFunction
(
owner in VarChar
,tableName in VarChar
) return integer authid current_user is
result Integer;
begin
execute immediate 'select count(*) from "' || owner || '"."' || tableName || '"'
INTO result;
return result;
end;
One option is to simply keep your DB statistics updated, use dbms_stats package or EM, and then
select num_rows
from all_tables
where table_name in (select name from table_list);
I think Robert Giesecke solution will work fine.
A more exotic way of solving this is by using dbms_xmlgen.getxml.
See for example: Identify a table with maximum rows in Oracle