Pls help me on how to implement CREATE TABLE AS SELECT
For simple create table t1 as select * from t2; I can implement as
Create table t1 like t2;
insert into t1 as select * from t2;
But how to implement create table t1 as select c1,c2,c3 from t2;
Is there any way to implement this in impala?
As mentioned in the comments, CREATE TABLE AS SELECT is supported in Impala since 1.2: documentation, JIRA ticket.
Related
I am trying to fetch set of records from the database part by part.
I tried to use Limit and fetch but it seems like it does not working with oracle 11g. Is there any alternative solution to do this. I have tried many in google results but nothing is working properly.
You can use this query and do what u want.
SELECT A.*
FROM (SELECT A.*, ROWNUM ROWNUMBER
FROM Table1 T
WHERE ROWNUM <= TO) T
WHERE ROWNUMBER > FROM;
FROM is from which number and TO is to which number
A Sound application is based on sound design. Kindly check if you are trying to achieve a procedural requirement using an SQL. If yes, it is better to use PL/SQL instead of SQL.
Create a cursor using the required SQL without any limits.
Create a type of associative array to hold the batch records.
Create an associative array using the type created above
Open and loop the cursor.
FETCH created_cursor BULK COLLECT INTO created_associated_array LIMIT ;
Hope this helps.
I created a database and having two tables like x and y. I cross joined them both and got an output.Now my question is can i save that output to a new table in the same database or different?
First you can try running the query SELECT * FROM table1 CROSS JOIN table2. Observe what columns are returned from the query, then create a new table new_table with columns of the appropriate type. Then you can try using INSERT INTO ... SELECT:
INSERT INTO new_table
SELECT * FROM table1 CROSS JOIN table2;
The CREATE TABLE statement directly accepts a query:
CREATE TABLE new_table AS
SELECT * FROM table1 CROSS JOIN table2;
(This will not keep the column types.)
The output can be saved in a different database if that database has been ATTACHed.
Kindly help me writing below query in openquery.Thanks in advance
INSERT INTO Tablename
SELECT * FROM tablename1 WHERE insertionorderid IN (
SELECT orderid FROM temp_table2)
If you are trying to insert into SQL Server the syntax would be
INSERT INTO dbo.[YOURTABLE] SELECT * FROM [MATCHING_TABLE] WHERE CLAUSE
The caveat here is that the two tables must have identical schemas or you will have to explicitly define the columns. Also this will not work properly for tables with identity columns
I can't seem to find documentation (that I understand) on how to list all tables in a database. I've tried the following:
SELECT * FROM .table;
SELECT * FROM .tab;
SELECT * FROM .db;
SELECT * FROM world.db;
None of them worked. I'm just learning SQL, so forgive my ignorance. :0)
Try this:
SELECT * FROM sqlite_master WHERE type='table'
If you are in interactive mode, you can use this:
.tables
Another method with extra information:
.schema
https://sqlite.org/cli.html#querying_the_database_schema
In my project, I have a database in SQL which was working fine. But now I have to make the application support oracle db too.
Some limitations I found out was that in Oracle, there is no bit field and the table name cannot be greater than 30 char. Is there any other limitation that I need to keep in mind.
Any suggestion from past experience will be helpful.
If I recall correctly from my earlier Oracle days:
there's no IDENTITY column specification in Oracle (you need to use sequences instead)
you cannot simply return a SELECT (columns) from a stored procedure (you need to use REF CURSOR)
of course, all stored procs/funcs are different (Oracle's PL/SQL is not the same as T-SQL)
The SQL ISNULL counterpart in Oracle is NVL
select ISNULL(col, 0)...
select NVL(col, 0)...
You will also struggle if you attempt to select without a from in Oracle. Use dual:
select 'Hello' from DUAL
Bear in mind also, that in Oracle there is the distinction between PL/SQL (Procedural SQL) and pure SQL. They are two distinct and separate languages, that are commonly combined.
Varchar in Oracle Databases called
varchar2 is limited to 4000
characters
Oracles concept of temporary tables is different, they have a global redefined structure
by default sort order and string compare is case-sensitive
When you add a column to a select *
Select * from table_1 order by id;
you must prefix the * by the table_name or an alias
Select
(row_number() over (order by id)) rn,
t.*
from table_1 t
order by id;
Oracle doesn't distinguish between null and '' (empty string). For insert and update you ca use '', but to query you must use null
create table t1 (
id NUMBER(10),
val varchar2(20)
);
Insert into t1 values (1, '');
Insert into t1 values (2, null);
Select * from t1 where stringval = 0; -- correct but empty
Select * from t1 where stringval is null; -- returns both rows
ORACLE do not support TOP clause. Instead of TOP you can use ROWNUM.
SQL Server: TOP (Transact-SQL)
SELECT TOP 3 * FROM CUSTOMERS
ORACLE: ROWNUM Pseudocolumn
SELECT * FROM CUSTOMERS WHERE ROWNUM <= 3