This question already has answers here:
Get counts of all tables in a schema
(6 answers)
Closed 5 years ago.
I need to find out the count of large number of tables (eg: 40,50 tables) in below format where I will provide the table set (as parameters or list of tables).
In other words, I need to find the count of tables as below for a user defined table set.
TABLE_NAME : ROW_COUNT
table_a : 1000000
table_b : 200000
table_c : 450000
table_d : 80000
etc..
1.) Is there a inbuilt option in sql developer or toad or any other tool to get count of multiple tables straight away?
2.) Is there a a sql statement or a pl/sql script that I can get above output?
Note: Please note that I don't want to get the count of all the tables in schema. I want only specific list of tables. Ex: lets say there is 100 tables in the schema but I want only the count of 25 tables which i mention
A PL/SQL Block like this will work. Uses EXECUTE IMMEDIATE to dynamically execute a query string formed from table names fetched from ALL_TABLES,
DECLARE
V_YOUR_SCHEMA VARCHAR2(30) ;
V_COUNT NUMBER;
BEGIN
V_YOUR_SCHEMA :='SCHEMA_NAME';
FOR L_TABLE_NAME IN (SELECT TABLE_NAME FROM ALL_TABLES WHERE SCHEMA_NAME = v_YOUR_SCHEMA)
LOOP
EXECUTE IMMEDIATE 'SELECT COUNT(*) FROM ' || v_YOUR_SCHEMA ||'.' ||L_TABLE_NAME INTO V_COUNT;
DBMS_OUTPUT.PUT_LINE(L_TABLE_NAME||' : '||V_COUNT);
END LOOP;
END;
/
Snippet for Defined list of table names:
DECLARE
V_YOUR_SCHEMA VARCHAR2(30) ;
V_COUNT NUMBER;
V_TABLE_LIST DBMS_SQL.VARCHAR2_TABLE;
TYPE V_LIST_TYPE is VARRAY(50) of VARCHAR2(30);
BEGIN
V_YOUR_SCHEMA :='SCHEMA_NAME';
V_TABLE_LIST V_LIST_TYPE := V_LIST_TYPE('TABLE1', 'TABLE2', 'TABLE3');
FOR L_ITER IN 1..V_TABLE_LIST.COUNT
LOOP
EXECUTE IMMEDIATE 'SELECT COUNT(*) FROM ' || v_YOUR_SCHEMA ||'.' ||V_TABLE_LIST(L_ITER) INTO V_COUNT;
DBMS_OUTPUT.PUT_LINE(V_TABLE_LIST(L_ITER)||' : '||V_COUNT);
END LOOP;
END;
/
Note: View ALL_TABLES also has a column num_rows, which is populated
only if you collect statistics on the table with the DBMS_STATS package.
Related
I have a 9 digit number, say "234234234", is there a way to find or check its appearance in my database, like in which particular schema or procedure does it fall? and list out all the tables and columns which has that value in pl/sql developer
This query only searches in stored objects that user is allowed to access (procedure, function, package, ...). You could refer to this
Not sure if there is one way to search for that value in all database table.
SELECT *
FROM all_source
WHERE text LIKE '%234234234%';
--AND owner = 'SCHEMA_NAME';
The below block identifies the given string's presence across all the tables in your DB.
declare
num_rows number;
sql_text varchar2(250);
sql_info varchar2(100);
begin
dbms_output.enable(1000000);
for x in (select table_name, column_name from dba_tab_columns
where data_type in ('VARCHAR','VARCHAR2','CHAR')
and owner <> 'SYSTEM')
loop
sql_text:='select count(*) into :num_rows from SYSTEM.'||x.table_name||' where '||x.column_name||' like ''%234234234%''';
-- dbms_output.put_line (sql_text);
execute immediate sql_text into num_rows;
if num_rows>0
then
sql_info:='Table: '||x.table_name||' contains the string';
dbms_output.put_line (sql_info);
end if;
end loop;
end;
/
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 found many such questions but the answers where all using Stored Procedures.
I want an answer that uses purely a query in Oracle Sql Developer.
I have a value 'CORE_AO0001031_70_EMail_1' but not sure in which table. The number of tables and the data inside them are very huge.
Doesn't matter if the query is huge and will take time to execute. Is there any such query?
The reason for my asking a query is, I don't have privilege to create a Stored Procedure and I won't be given that privilege. Please help me with a query.
With an SQL you can't, as the queries are going to be dynamic. You have to execute a PL/SQL atleast.
Note: This is a Costly operation!
You can still attempt a full download of all you tables as spooling, and make PERL search into all files. In that case, you need a lot of disk space, but less harm(Just better than the Pl/SQL) to the database
DECLARE
TYPE TY_TABLE_NAMES IS TABLE OF VARCHAR2(30);
L_TABLE_NAMES TY_TABLE_NAMES;
TYPE TY_COLUMN_NAMES IS TABLE OF VARCHAR2(30);
L_COLUMN_NAMES TY_COLUMN_NAMES;
v_SCHEMA_NAME VARCHAR2(30) = 'SYSTEM'; --Your Schema Name
v_QUERY_STRING VARCHAR2(4000);
v_SEARCH_STRING VARCHAR2(4000) := 'CORE_AO0001031_70_EMail_1';
v_SEARCH_FLAG CHAR(1) := 'N';
BEGIN
SELECT ALL_TABLES
BULK COLLECT INTO L_TABLE_NAMES
WHERE OWNER = v_SCHEMA_NAME;
FOR I In 1..L_TABLE_NAMES.COUNT LOOP
SELECT COLUMN_NAME
BULK COLLECT INTO L_COLUMN_NAMES
FROM ALL_TAB_COLUMNS
WHERE TBALE_NAME = L_TABLE_NAMES(I)
AND OWNER = v_SCHEMA_NAME;
FOR J In 1..L_COLUMN_NAMES.COUNT LOOP
BEGIN
v_QUERY_STRING := 'SELECT ''Y'' FROM DUAL WHERE EXISTS (SELECT ''X'' FROM '||L_TABLE_NAMES(I)||' WHERE '||
||L_COLUMN_NAMES(J)|| ' LIKE ''%'|| v_SEARCH_STRING||'%'')';
EXCECUTE IMMEDIATE v_QUERY_STRING INTO v_SEARCH_FLAG;
WHEN NO_DATA_FOUND THEN
v_SEARCH_FLAG := 'N';
END;
IF(v_SEARCH_FLAG = 'Y') THEN
DBMS_OUTPUT.PUT_LINE(v_SEARCH_STRING || ' found in column '||L_COLUMN_NAMES(I)|| ' of table '||L_TABLE_NAMES(I));
BREAK;
END IF;
END LOOP;
IF(v_SEARCH_FLAG = 'Y') THEN
DBMS_OUTPUT.PUT_LINE('Done Searching!');
BREAK;
END IF;
END LOOP;
END;
/
A database has a lot of columns (more than 100). Some of these columns have null entries. How can I find out how many columns have null entries in at least one row, without manually testing each and every column?
Try:
declare
l_count integer;
begin
for col in (select table_name, column_name
from user_tab_columns where table_name='EMP')
loop
execute immediate 'select count(*) from '||col.table_name
||' where '||col.column_name
||' is not null and rownum=1'
into l_count;
if l_count = 0 then
dbms_output.put_line ('Column '||col.column_name||' contains only nulls');
end if;
end loop;
end;
Try analyzing your table (compute statistics, don't estimate) and then (immediately) do:
select column_name, num_nulls
from all_tab_columns
where table_name = 'SOME_TABLENAME'
and owner = 'SOME_OWNER';
Of course as data later changes, this will become slightly more incorrect. If you need to get more fancy and do a field population count (fieldpop), then you'll need to loop through all rows and check for nulls explicitly (and exclude any other values you deem "not populated", perhaps a default of 0 for a number field for example).
I can give you the direction in which to research:
Check "user_tab_columns" through which you can get information related to columns in a table.
E.g.
select count(*) from user_tab_columns where table_name = 'YOURTABLENAME'
This gives you the number of columns in that table.
Together with this you would need to use a cursor, i think, to check each column for null values rather than adding a null check in WHERE clause for each column.
This will give you the number of NULL column values per row of data:
declare
TYPE refc IS REF CURSOR;
col_cv refc;
l_query varchar(3999);
v_rownum number;
v_count number;
begin
l_query := 'select rownum, ';
for col in (select table_name, column_name
from user_tab_columns where table_name='EMP')
loop
l_query := l_query ||'DECODE('||col.column_name||',NULL,1,0)+';
end loop;
l_query := l_query||'+0 as no_of_null_values from EMP';
DBMS_OUTPUT.PUT_LINE(l_query);
OPEN col_cv FOR l_query;
LOOP
FETCH col_cv into v_rownum, v_count;
EXIT WHEN col_cv%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(v_rownum || ' ' || v_count);
END LOOP;
CLOSE col_cv;
end;
I feel dirty even writing it! (It won't work when the number of columns in the table is very large and l_query overflows).
You just need to change the table name (EMP above).
How can we Search for a given string in all fields of an entire schema for Oracle?
is there an sql script to do the above in Oracle? if yes, how?
Can we do it by any other script?
"ALL_TAB_COLUMNS" is a systable, have all table columns data type etc.
"USER_TAB_COLUMNS" is a systable, have all table columns data type etc (which owner is current user). (Thanks Rene)
An Example:
SET SERVEROUTPUT ON SIZE 100000 -- maybe you have a lot of table and columns
DECLARE
matches INTEGER;
BEGIN
FOR columns IN (SELECT table_name, column_name FROM user_tab_columns where data_type = 'VARCHAR2') LOOP
EXECUTE IMMEDIATE
'SELECT COUNT(*) FROM '||t.table_name||' WHERE instr('||t.column_name||' , :1) > 0'
INTO matches
USING 'What you search';
IF matches > 0 THEN
dbms_output.put_line( t.table_name ||' '||t.column_name||' '||matches );
END IF;
END LOOP;
END;
/
this query will output table_name '' column_name'' and count, if you have standart column and table names, you can change query as IF columns > 0 then write a query UNION in loop and return the cursor, or return a table,
Can we do it by any other script?
You can dump the database to disk as text, then use grep.