I have a simple, as it looks, question:
I am having Sqlite query where I am using temp tables and then joining those table, something like:
drop table if exists SourceA
create temp table SourceA (id int, value text);
insert into SourceA select id, value from TableA
drop table if exists SourceB
create temp table SourceB (id int, value text);
insert into SourceB select id, value from TableB
select SourceA.*, SourceB.* from SourceA join SourceB on SourceA.id = SourceB.id
Now is it possible to create some sort of procedura if or case so for example one of those insert will not be executed, like:
bool merge = false;
drop table if exists SourceA
create temp table SourceA (id int, value text);
insert into SourceA select id, value from TableA
if(merge)
{
drop table if exists SourceB
create temp table SourceB (id int, value text);
insert into SourceB select id, value from TableB
select SourceA.*, SourceB.* from SourceA join SourceB on SourceA.id = SourceB.id
else
{
select * from SourceA
}
Example of usage is simple, its like a condition when you determine seconds two dates, let's say second table counts missing seconds, so now if interval is too big app will crush. So i need to determine outside of SQL if such thing can be done, and pass it to SQL (basically it can be any condition that will exclude second insert from happening)
I've mange to handle my problem by using variables temp table like:
drop table if exists Variables;
create temp table Variables (MinDatetime Datetime, MaxDatetime Datetime);
insert into Variables Values(#MinDatetime, #MaxDatetime);
And then passing parameter from code, an just omitting result using case something like:
case when (Select MinDatetime from Variables) = 'None' or (Select MaxDatetime from Variables) = 'None' then 0
else value
end as value
And if value is 'None' it will return just plain 0
SQLite is designed as an embedded database, to be used together with a 'real' programming language, so it does not have any procedural features.
Put the control logic into your actual program (or, if you don't have one, write a script).
Related
I'm trying to run this specific code for a temp table, but somehow I get this error
Column name or number of supplied values does not match table definition
What's wrong?
DROP TABLE IF EXISTS #GamesDistribution
CREATE TABLE #GamesDistribution
(
Platform nvarchar(255),
Name nvarchar(255),
NA_Sales numeric,
EU_Sales numeric,
JP_Sales numeric
)
INSERT INTO #GamesDistribution
SELECT
properties.Platform,
properties.Name,
revenue.NA_Sales,
revenue.EU_Sales,
revenue.JP_Sales
FROM
games_properties AS Properties
JOIN
games_revenue AS Revenue ON properties.Game_ID = Revenue.Game_ID
--GROUP BY properties.platform
--ORDER BY Total_Games DESC, Total_NA_Sales DESC, Total_EU_Sales DESC, Total_JP_Sales DESC;
The problem here is that prior to you running your batch the table already exists. As such when the batch is parsed, by the compiler, the compilation fails; because the number of columns doesn't match that of the table already exists.
This can be replicated with the following:
CREATE TABLE #t (I int);
INSERT INTO #t (I)
VALUES(1);
GO
DROP TABLE IF EXISTS #t;
CREATE TABLE #t (I int, D date);
INSERT INTO #t
VALUES(2,GETDATE());
GO
SELECT *
FROM #t;
GO
DROP TABLE #t
db<>fiddle
This returns the error:
Msg 213, Level 16, State 1, Line 10
Column name or number of supplied values does not match table definition.
And the dataset:
I
1
This is because the 2nd batch, with the DROP TABLE IF EXISTS never ran; the compilation failed.
The "simple" solution here would be to put your DROP IF EXISTS in a separate batch, and also specify your columns:
DROP TABLE IF EXISTS #GamesDistribution;
GO
CREATE TABLE #GamesDistribution (Platform nvarchar(255),
Name nvarchar(255),
NA_Sales numeric, --Where is your precision and scale?
EU_Sales numeric, --Where is your precision and scale?
JP_Sales numeric); --Where is your precision and scale?
INSERT INTO #GamesDistribution (Platform,Name, NA_Sales,EU_Sales,JP_Sales)
SELECT properties.Platform,
properties.Name,
revenue.NA_Sales,
revenue.EU_Sales,
revenue.JP_Sales
FROM dbo.games_properties AS Properties
JOIN dbo.games_revenue AS Revenue ON properties.Game_ID = Revenue.Game_ID;
You can actually do this way
DROP TABLE IF EXISTS #GamesDistribution
SELECT properties.Platform,
properties.Name,
revenue.NA_Sales,
revenue.EU_Sales,
revenue.JP_Sales
INTO #GamesDistribution
FROM games_properties AS Properties
JOIN games_revenue AS Revenue
ON properties.Game_ID = Revenue.Game_ID
and then you can check the columns' data types of the temp table:
EXEC tempdb..sp_help '#GamesDistribution'
SELECT *
FROM tempdb.sys.columns
WHERE [object_id] = OBJECT_ID('tempdb..#GamesDistribution');
Note: It's always better to ensure the columns' data types. Your query might list different columns' data types.
Add GO statement under drop table as below.
DROP TABLE IF EXISTS #GamesDistribution
GO
CREATE TABLE #GamesDistribution
(
.
.
.
I have a MEMBER table and NOTIFICATION table. On client side, I list all of the records in MEMBER table and there is a points column and this is shown as text input. So after I change the values for some members, I can click save button and this will update the records in my MEMBER table that's all right,
But the thing I want to accomplish is for every record whose points value has changed I want to INSERT a record in my notifications table.
I couldn't think of anything, how can I approach to this problem?
For notifications I made 3 tables by following the article in here
Use the output clause instead of trigger, they are bad.
You need the condition "where data_old <> data_new" case if you updated a column with the same value, SQL Server marked it as changed, even if the value hasn't changed
create table #example (id int identity(1,1) not null, data nvarchar(max));
insert into #example (data) values ('value 1'),('value 2'), ('value 3');
create table #audit (id int, data_old nvarchar(max), data_new nvarchar(max), [When] datetime not null default (getdate()));
insert into #audit (id, data_old, data_new)
select id, data_old, data_new
from (
update #example
set data = 'value changed'
output inserted.id, deleted.data as data_old, inserted.data as data_new
where id = 2
)changed (id, data_old, data_new)
where data_old <> data_new
select * from #audit
will result with this in #audit :
You have described what a trigger does.
create trigger trig_member_insert on members after update
as
begin
insert into notifications ( . . . )
select . . ., i.points as new_points u.points as old_points -- what you want to insert
from inserted i join
updated u
on i.member_id = u.member_id
where u.points <> i.points
end;
Storing something called "points" as a string seems like a very poor choice. It sounds like a number.
This may be a very basic question, but I have been struggling with this.
I have a SSMS query that I'll be using multiple times for a large set of client Ids. Its quite cumbersome to have to amend the parameters in all the where clauses every time I want to run it.
For simplicity, I want to convert a query like the one below:
SELECT
ID,
Description
From TestDb
Where ID in ('1-234908','1-345678','1-12345')
to a query of the format below so that I only need to change my variable field once and it can be applied across my query:
USE TestDb
DECLARE #ixns NVARCHAR(100)
SET #ixns = '''1-234908'',''1-345678'',''1-12345'''
SELECT
ID,
Description
From TestDb
Where ID IN #ixns
However, the above format doesn't work. Can anyone help me on how I can use a varchar/string variable in my "where" clause for my query so that I can query multiple IDs at the same time and only have to adjust/set my variable once?
Thanks in advance :D
The most appropriate solution would be to use a table variable:
DECLARE #ixns TABLE (id NVARCHAR(100));
INSERT INTO #ixns(id) VALUES
('1-234908'),
('1-345678'),
('1-12345');
SELECT ID, Description
FROM TestDb
WHERE ID IN (SELECT id FROM #ixns);
You can load ids to temp table use that in where condition
USE TestDb
DECLARE #tmpIDs TABLE
(
id VARCHAR(50)
)
insert into #tmpIDs values ('1-234908')
insert into #tmpIDs values ('1-345678')
insert into #tmpIDs values ('1-12345')
SELECT
ID,
Description
From TestDb
Where ID IN (select id from #tmpIDs)
The most appropriate way is to create a table type because it is possible to pass this type as parameters.
1) Creating the table type with the ID column.
create type MyListID as table
(
Id int not null
)
go
2) Creating the procedure that receives this type as a parameter.
create procedure MyProcedure
(
#MyListID as MyListID readonly
)
as
select
column1,
column2
...
from
MyTable
where
Id in (select Id from #MyListID)
3) In this example you can see how to fill this type through your application ..: https://stackoverflow.com/a/25871046/8286724
I have a table variable with about 20 columns. I'd like to essentially reuse a single table variable structure for 2 different result sets. The 2 result sets should be represented in different table variables so I can't reuse a single table variable. Therefore, I was wondering if there was a way to clone a single table variable for reuse. For example, something like this:
DECLARE #MyTableVar1 TABLE(
Col1 INT,
Col2 INT
}
DECLARE #MyTableVar2 TABLE = #MyTableVar1
I'd like to avoid creating duplicate SQL if I can reuse existing SQL.
That is not possible, use temp table instead
if object_id('tempdb..#MyTempTable1') is not null drop table #MyTempTable1
Create TABLE #MyTempTable1 (
Col1 INT,
Col2 INT
)
if object_id('tempdb..#MyTempTable2') is not null drop table #MyTempTable2
select * into #MyTempTable2 from #MyTempTable1
update :
As suggested by Eric in comment, if you are looking for just table schema and not the data inside the first table then
select * into #MyTempTable2 from #MyTempTable1 where 1 = 0
You can create a user-defined table type which is typically meant for using table valued parameters for stored procedures. Once the type is created, you can use it as a type to declare any number of table variables just like built-in types. This comes closest to you requirement.
Ex:
CREATE TYPE MyTableType AS TABLE
( COL1 int
, COL2 int )
DECLARE #MyTableVar1 AS MyTableType
DECLARE #MyTableVar2 AS MyTableType
A few things to note with this solution
MyTableType becomes a database level type. It is not local to a specific stored procedure.
If you have to ever change the definition of the table, then you have to drop the code/sprocs using the TVP type, then recreate the table type with new definition and related sprocs. Typically this is a non-issue as the code and the type are created/recreated together.
You could use a temp table and select into... they perform better since their statistics are better.
create table #myTable(
Col1 INT null,
Col2 INT null
}
...
select *
into #myTableTwo
from #myTable
You can create one table variable and add type column in the table and use the type column in your queries to filter the data.
By this you are using one table to hold more than one type of data.
Hope this helps.
declare #myTable table(
Col1 INT null,
Col2 INT null,
....
Type INT NULL
}
insert into #myTable(...,type)
select ......,1
insert into #myTable(...,type)
select ......,2
select * from #myTable where type =1
select * from #myTable where type =2
I have a table designed like,
create table tbl (
id number(5),
data blob
);
Its found that the column data have
very small size data, which can be stored in raw(200):
so the new table would be,
create table tbl (
id number(5),
data raw(200)
);
How can I migrate this table to new design without loosing the data in it.
This is a bit lengthy method, but it works if you are sure that your data column values don't go beyond 200 in length.
Create a table to hold the contents of tbl temporarily
create table tbl_temp as select * from tbl;
Rem -- Ensure that tbl_temp contains all the contents
select * from tbl_temp;
Rem -- Double verify by subtracting the contents
select * from tbl minus select * from tbl_temp;
Delete the contents in tbl
delete from tbl;
commit;
Drop column data
alter table tbl drop column data;
Create a column data with raw(200) type
alter table tbl add data raw(200);
Select & insert from the temporary table created
insert into tbl select id, dbms_lob.substr(data,200,1) from tbl_temp;
commit;
We are using substr method of dbms_lob package which returns raw type data. So, the resulted value can be directly inserted.