I am new with SAP HANA, I am trying to generate a query and execute it within a stored procedure.
I got an error and I am not sure that HANA can do something like that.
Here my code
CREATE PROCEDURE "PROCEDURE_IBA_TESTCSV"(
IN SCHEMA_NAME VARCHAR(100))
LANGUAGE SQLSCRIPT SQL SECURITY INVOKER AS
BEGIN
DECLARE T VARCHAR(1000);
DECLARE TA VARCHAR(1000);
SELECT
' SELECT ' || MAX(C_1) || IFNULL(MAX(C_2),'')|| IFNULL(MAX(C_3),'') ||' AS STATEMENT FROM ' || SCHEMA_NAME || '.' || TABLE_NAME || ' ' INTO T
FROM (
SELECT POSITION, DATA_TYPE_ID, COLUMN_NAME ,SCHEMA_NAME, TABLE_NAME ,
CASE WHEN POSITION = 1 THEN
' CASE WHEN ( '|| COLUMN_NAME ||' IS NULL ) THEN '''' ELSE REPLACE(TO_CHAR(' || COLUMN_NAME || '),''.'','','') END' END AS C_1,
CASE WHEN POSITION = 2 THEN '||''#''|| CASE WHEN ( '|| COLUMN_NAME ||' IS NULL ) THEN '''' ELSE TO_NVARCHAR('||COLUMN_NAME||') END' END AS C_2,
CASE WHEN POSITION = 3 THEN '||''#''|| CASE WHEN ( '|| COLUMN_NAME ||' IS NULL ) THEN '''' ELSE TO_NVARCHAR('||COLUMN_NAME||') END' END AS C_3
FROM (
select SCALE,SCHEMA_NAME,position,TABLE_NAME,column_name, data_type_id from TABLE_COLUMNS where
schema_name ='IMPORT_KT_STAMM_IK_348BA_20160706' AND TABLE_NAME='CLS_220_KTHISTORIE')) group by SCHEMA_NAME,TABLE_NAME;
execute immediate :T ;
INSERT INTO Test SELECT :T from DUMMY;
END;
With execute :T I get this output
I would like to store SUM(length) of this output into a variable within the same procedure.
Is that possible ? Any help ?
thanks in advance
Ok, now I understand, where this is going.
As you want to work with tables of different shape, you won't be able to avoid dynamic SQL altogether.
But since you always melt it into a single column, you could simply store that transformed data into, say a temporary table, and run the SUM(LENGTH(()) on that.
Not sure though why you want to go through this rather painful exercise, instead of simply exporting the data into some folder and checking the resulting size there.
I don't quite get why you use dynamic SQL here. With dynamic SQL (exec/execute immediate) you don't get access to the result set.
Alternatively you can use cursors.
You can provide parameters for SCHEMA_NAME and TABLE_NAME and be 'dynamic' that way.
I guess this question is related to SAP HANA getting csv data size right?
I modified my code:
I write "insert into Table SELECT " instead "SELECT" in line 8
and now I get data in table
Related
Quick Disclaimer:
First thing out of the way, I know the preferred way of handling dynamic SQL in Oracle now is the DBMS_SQL package but unfortunately my application team does not have the grants to execute these procs at the moment and I am hoping to get this quick workaround knocked out before our DBA team gets back to me. Also, this database is on Oracle 12c.
Script Goal: I recently developed a Stored Proc (let's call it Original) that uses values in a "control table" to make a large number of updates to certain columns in a database with many schemas and tables. This script I am struggling with now (let's call it Test) is meant to be a quick loop through those columns affected by Original so as to verify that everything worked expectedly. Ultimately, I want to output the top 5 results of each changed column and hand a spooled file to my testing team for validation.
The control_table used in both scripts has 4 columns and looks like this:
OWNER
TABLE_NAME
COLUMN_NAME
ALGORITHM
Schema1
TableA
ColumnA
Method1
Schema1
TableB
ColumnB
Method1
Schema2
TableC
ColumnC
Method2
An example of one of the tables that gets updated by Original (let's say for TableA above) would be:
OtherCol1
OtherCol2
ColumnA
OtherCol3
Ignored
Ignored
UpdatedData1
Ignored
Ignored
Ignored
UpdatedData2
Ignored
Ignored
Ignored
UpdatedData3
Ignored
Issue with Test script: I have the dynamic SQL - I believe - working as it needs and I have been trying to figure out how best to print the results of the EXECUTE IMMEDIATE command to output. In doing some reading, I found that BULK COLLECT INTO should allow me to store the results of the dynamic queries into a COLLECTION which I can then print with dbms_output. I have attempted to do this with both a TABLE and a VARRAY but in both cases when I print, I am finding that the data stored in my collection is the column header of my dynamic query instead of the query values! The only thing I can think that could be the problem is the combining of BULK COLLECT INTO with the USING command when I run the dynamic statement but I have seen nothing in the documentation to indicate that these two commands are incompatible and my Test procedure below compiles without issue (and even seems to run ok).
Test Script:
SET SERVEROUTPUT ON SIZE UNLIMITED;
DECLARE
l_script VARCHAR2(500);
l_errm VARCHAR2(64);
TYPE results IS VARRAY(5) OF VARCHAR2(250);
va_cols results; --Defining here with a VARRAY but I have also tried with a table
BEGIN
FOR c_col IN(
SELECT owner, table_name, column_name, algorithm FROM control_list)
LOOP
l_errm := NULL;
va_cols := NULL;
BEGIN
dbms_output.put_line('Column '|| c_col.column_name || ' of table ' || c_col.owner ||
'.' || c_col.table_name || ' used algorithm ' || c_col.algorithm);
l_script := 'SELECT :1 FROM ' || c_col.owner || '.' || c_col.table_name ||
' WHERE :2 IS NOT NULL FETCH FIRST 5 ROWS ONLY';
dbms_output.put_line('Script sent to Exec Immediate: ' || l_script); --Print l_script for debugging
EXECUTE IMMEDIATE l_script BULK COLLECT INTO va_cols USING c_col.column_name, c_col.column_name;
dbms_output.put_line(va_cols(1));
dbms_output.put_line(va_cols(2));
dbms_output.put_line(va_cols(3));
dbms_output.put_line(va_cols(4));
dbms_output.put_line(va_cols(5));
EXCEPTION
WHEN OTHERS THEN
l_errm := SUBSTR(SQLERRM, 1, 64);
dbms_output.put_line(' ERROR: ' || l_errm || '. Skipping row');
CONTINUE;
END;
END LOOP;
END;
/
So my intended dbms_output of the script above is:
Column ColumnA of table Schema1.TableA used algorithm Method1
Script sent to Exec Immediate: SELECT :1 FROM SCHEMA1.TABLEA WHERE :2 IS NOT NULL FETCH FIRST 5 ROWS ONLY
UpdatedData1
UpdatedData2
UpdatedData3
UpdatedData4
UpdatedData5
Instead, however, bizarrely, what I am getting when I run this is:
Column ColumnA of table Schema1.TableA used algorithm Method1
Script sent to Exec Immediate: SELECT :1 FROM SCHEMA1.TABLEA WHERE :2 IS NOT NULL FETCH FIRST 5 ROWS ONLY
ColumnA
ColumnA
ColumnA
ColumnA
ColumnA
Has anyone seen this before and know what I am doing wrong? Thanks in advance!!
You can't use bind variables to change what columns you're referencing. You use bind variables to specify particular values at runtime. When you do
l_script := 'SELECT :1 FROM ' || c_col.owner || '.' || c_col.table_name ||
' WHERE :2 IS NOT NULL FETCH FIRST 5 ROWS ONLY';
EXECUTE IMMEDIATE l_script BULK COLLECT INTO va_cols USING c_col.column_name, c_col.column_name;
you're telling Oracle that you want to select the literal string in the variable c_col.column_name. Not the column in the table by that name. Which is why every row returns that literal value.
You'd need to dynamically assemble the SQL statement with the column names, not try to use them as bind variables. So something like
l_script := 'SELECT ' || c_col.column_name ||
' FROM ' || c_col.owner || '.' || c_col.table_name ||
' WHERE ' || c_col.column_name || ' IS NOT NULL FETCH FIRST 5 ROWS ONLY';
EXECUTE IMMEDIATE l_script BULK COLLECT INTO va_cols;
This is approximately what you want. I outer cursor over tables and column to inspect that generate the dynamic SQL.
Inner loop reading the column values from the previous query
DECLARE
TYPE CurTyp IS REF CURSOR;
v_cursor CurTyp;
v_value VARCHAR2(200);
v_stmt_str VARCHAR2(200);
BEGIN
FOR c IN (
SELECT table_name, column_name FROM control_list)
LOOP
dbms_output.put_line('tab: '||c.table_name);
v_stmt_str := 'SELECT '||c.column_name||' FROM '|| c.table_name;
OPEN v_cursor FOR v_stmt_str;
LOOP
FETCH v_cursor INTO v_value;
EXIT WHEN v_cursor%NOTFOUND;
dbms_output.put_line('col: '||c.column_name||' val: '||v_value);
END LOOP;
END LOOP;
CLOSE v_cursor;
END;
/
In Oracle PL/SQL, I have run a query and am trying to read through each column for each row one by one so I can concatenate them together with a delimiter (hard format requirement). The script is used on multiple tables of varying sizes, so the number of columns is not known in advance. I used
SELECT COUNT(column_name) INTO NumColumns FROM all_tabs_cols
WHERE table_name = Table_Array(i);
where Table_Array has already been defined. This is in the middle of a for loop and has successfully gotten me a total number of columns. Table_Cursor is a SELECT * statement. After this I am trying to do something like
FOR j IN 0..NumColumns-1 LOOP
FETCH TABLE_CURSOR.column(j) INTO DataValue;
DBMS_OUTPUT.PUT(DataValue || '/');
END LOOP
The above is pseudo code. It illustrates the concept I am after. I do not know PL/SQL well enough to know how to get a value like this out of a row. I am also worried about accidentally advancing the cursor while doing this. How can I accomplish this task?
You must use some form of dynamic SQL. Here is a quick example:
It builds the SQL statement that will select the '/' separated columns from the table you want. Then it uses dynamic SQL to run that SQL statement.
DECLARE
p_table_name VARCHAR2(30) := 'DBA_OBJECTS';
l_sql VARCHAR2(32000);
TYPE varchar2tab IS TABLE OF VARCHAR2(32000);
l_array varchar2tab;
BEGIN
SELECT 'SELECT ' || listagg(column_name,' ||''/''||') within group ( order by column_id ) || ' FROM ' || owner || '.' || table_name || ' WHERE ROWNUM <= 100'
INTO l_sql
FROM dba_tab_columns
where table_Name = 'DBA_OBJECTS'
group by owner, table_Name;
EXECUTE IMMEDIATE l_sql BULK COLLECT INTO l_array;
FOR i in l_array.first .. l_array.last LOOP
dbms_output.put_line(l_array(i));
END LOOP;
END;
This is how your code should look:
SELECT F1 || ', ' || F2 || ', ' || ... || ', ' || FN
FROM TABLE
NO LOOPS
Here is how you can generate code that does not use loops.
Note, if you want you can take out the where statement and generate the code for the whole database.
Test with just one table first.
SELECT 'SELECT '|| LISTAGG(COLUMN_NAME, ' || '', '' || ') || ' FROM '||TABLE_NAME as sql_stm
FROM ALL_TAB_COLUMNS
WHERE TABLE_NAME='tablename'
GROUP BY TABLE_NAME;
I am a beginner with SQL and have a problem:
I have a DB with a big number of tables. Some of the tables have a column with the name "lab".
In this colums are values I need to be changed.
So I managed to get the names of the tables via
SELECT CNAME,TNAME FROM SYSTEM.COL WHERE CNAME = 'LAB';
And I know my update command
update TNAME set LAB='VALUE' WHERE LAB='OLDVALUE'
But I can not manage to connect both statements via a variable TNAME or something. I tried to use execute immediate, but that did me no good.
If its Oracle, something like this should do it:
BEGIN
FOR cur_tabs_cols IN ( SELECT CNAME,TNAME FROM SYSTEM.COL WHERE CNAME = 'LAB'; )
LOOP
EXECUTE IMMEDIATE 'UPDATE ' || cur_tabs_cols.TNAME || ' SET LAB = ''VALUE'' WHERE LAB = ''OLDVALUE''';
END LOOP;
COMMIT;
END;
You would need to write pl/sql for this.
The first thing is, please don't use SYSTEM.COL. Instead use the data dictionary view USER_TAB_COLS or USER_TAB_COLUMNS. (or ALL_TAB_COLS if in other schema)
EXECUTE IMMEDIATE would be what you want here.
BEGIN
FOR i IN (SELECT table_name
FROM user_tab_cols
WHERE column_name = 'LAB')
LOOP
EXECUTE IMMEDIATE
'UPDATE ' || i.table_name || ' set LAB = :value where LAB = :oldvalue'
USING 'value', 'oldvalue';
END LOOP;
END;
You can (and should) use a bind variable for value and oldvalue, just not for the table name.
I need to get the maximum length of data per each column in a bunch of tables. I'm okay with doing each table individually but I'm looking for a way to loop through all the columns in a table at least.
I'm currently using the below query to get max of each column-
select max(length(exampleColumnName))
from exampleSchema.exampleTableName;
I'm basically replacing the exampleColumnName with each column in a table.
I've already went through 3-4 threads but none of them were working for me either because they weren't for Oracle or they had more details that I required (and I couldn't pick the part I needed).
I'd prefer to have it in SQL than in PLSQL as I don't have any create privileges and won't be able to create any PLSQL objects.
Got the below query to work -
DECLARE
max_length INTEGER; --Declare a variable to store max length in.
v_owner VARCHAR2(255) :='exampleSchema'; -- Type the owner of the tables you are looking at
BEGIN
-- loop through column names in all_tab_columns for a given table
FOR t IN (SELECT table_name, column_name FROM all_tab_cols where owner=v_owner and table_name = 'exampleTableName') LOOP
EXECUTE IMMEDIATE
-- store maximum length of each looped column in max_length variable
'select nvl(max(length('||t.column_name||')),0) FROM '||t.table_name
INTO max_length;
IF max_length >= 0 THEN -- this isn't really necessary but just to ignore empty columns. nvl might work as well
dbms_output.put_line( t.table_name ||' '||t.column_name||' '||max_length ); --print the tableName, columnName and max length
END IF;
END LOOP;
END;
Do let me know if the comments explain it sufficiently, else I'll try to do better. Removing table_name = 'exampleTableName' might loop for all tables as well, but this is okay for me right now.
You can try this; although it uses PL/SQL it will work from within SQL-Plus. It doesn't loop. Hopefully you don't have so many columns that the SELECT query can't fit in 32,767 characters!
SET SERVEROUTPUT ON
DECLARE
v_sql VARCHAR2(32767);
v_result NUMBER;
BEGIN
SELECT 'SELECT GREATEST(' || column_list || ') FROM ' || table_name
INTO v_sql
FROM (
SELECT table_name, LISTAGG('MAX(LENGTH(' || column_name || '))', ',') WITHIN GROUP (ORDER BY NULL) AS column_list
FROM all_tab_columns
WHERE owner = 'EXAMPLE_SCHEMA'
AND table_name = 'EXAMPLE_TABLE'
GROUP BY table_name
);
EXECUTE IMMEDIATE v_sql INTO v_result;
DBMS_OUTPUT.PUT_LINE(v_result);
END;
/
I want to write a PLSQL stored procedure that accepts a table name as argument. This table is source table. Now inside my procedure i want to manipulate the fields of that table.
EX: I want to insert the records of this source table into another target table whose name is XYZ_<source table name>. The column names for source and target tables are the same. But there may be some extra fields in target table. How do i do it? The order of column names is not same.
You will have to build the INSERT statement dynamically.
create or replace procedure gen_insert
(p_src_table in user_tables.table_name%type
, p_no_of_rows out pls_integer)
is
col_str varchar2(16000);
begin
for rec in ( select column_name
, column_id
from user_tab_columns
where table_name = p_src_table
order by column_id )
loop
if rec.column_id != 1 then
col_str := col_str || ',' || rec.column_name;
else
col_str := rec.column_name;
end if:
end loop;
execute immediate 'insert into xyz_' || p_src_table || '('
|| col_str || ')'
|| ' select ' || col_str
|| ' from ' || p_src_table;
p_no_of_rows := sql%rowcount;
end;
/
Obviously you may want to include some error handling and other improvements.
edit
Having edited your question I see you have a special requirement for naming the target table which was obscured by the SO formatting.
You can do this using Dynamic SQL. Here's a link with basic info on Oracle Dynamic SQL