I'm not very familiar with SQL Server and T-SQL so I was trying to understand what was being inserted into this table. I think it's just field or column names being inserted since there is no FROM statement but the syntax looks strange to me. Obviously the one insertion is a variable. What are the 0s in front? I I've only dealt with MySQL.
INSERT INTO EXAMPLETABLE
SELECT
#RANDOMEVARIABLE IDTYPE, 0 foofoofoo, 0 foofoo, 0 foo
One record will be inserted. The value of #RANDOMEVARIABLE will be stored in the first column and 0 will be stored in the next 3 columns. Since all of the values are constants (and one local variable) no FROM is required.
Note that the order and names of the columns in the SELECT part are irrelevant. The data will be mapped to the column in the order they exist in the destination table (the types must be compatible as well). For that reason it's typically better to specify the column:
INSERT INTO EXAMPLETABLE
VALUES (IDTYPE, foofoofoo, foofoo, foo)
SELECT #RANDOMEVARIABLE IDTYPE, 0 foofoofoo, 0 foofoo, 0 foo
You would get the same results by not supplying column aliases:
INSERT INTO EXAMPLETABLE
SELECT #RANDOMEVARIABLE, 0, 0, 0
Related
I have 10 tables of which 4 tables have 99 columns and 6 tables have 100 columns. I have to combine using UNION ALL. when executing SQL query getting below error
Msg 205, Level 16, State 1, Line 6
All queries combined using a UNION, INTERSECT or EXCEPT operator must have an equal number of expressions in their target lists.
I understood the reason of error is for not same number of columns. I tried using NULL as Column100 but still getting same error.
please can anyone suggest me how to use * and UNION ALL in SQL query.
Thanks.
If the extra column happens to be at the beginning or end and the other columns are in exactly the same order, then you can add the column manually:
select t99.*, 't99' as col
from t99
union all
select t100.*
from t100;
But really, is it that hard to list the columns? An explicit column list is much less prone to error. And, it will work regardless of where the 100th column appears.
You can get the list in SQL Server Management Studio by clicking on the table name. You can also run a query such as:
select column_name
from information_schema.columns
where table_name = 't99';
And then use the column names to construct the query (I often use a spreadsheet for this purpose).
UNION requres that columns before and after it MATCH.
You can not do union of 99 columns and then 100 columns. You have to either provide dummy value for 100th column that do not exist in that table, or tell DB to skipp that column.
So add to the smaller table select:
NULL AS missing-column-name
Or list all the common columns by hand omitting columns that do not exists in both.
I'm trying to randomly populate a column with values from another table using this statement:
UPDATE dbo.SERVICE_TICKET
SET Vehicle_Type = (SELECT TOP 1 [text]
FROM dbo.vehicle_typ
WHERE id = abs(checksum(NewID()))%21)
It seems to work fine, however the value NULL is inserted into the column. How can I get rid of the NULL and only insert the values from the table?
This can happen when you don't have an appropriate index on the ID column of your vehicle_typ table. Here's a smaller query that exhibits the same problem:
create table T (ID int null)
insert into T(ID) values (0),(1),(2),(3)
select top 1 * from T where ID = abs(checksum(NewID()))%3
Because there's no index on T, what happens is that SQL Server performs a table scan and then, for each row, attempts to satisfy the where clause. Which means that, for each row it evaluates abs(checksum(NewID()))%3 anew. You'll only get a result if, by chance, that expression produces, say, 1 when it's evaluated for the row with ID 1.
If possible (I don't know your table structure) I would first populate a column in SERVICE_TICKET with a random number between 0 and 20 and then perform this update using the already generated number. Otherwise, with the current query structure, you're always relying on SQL Server being clever enough to only evaluate abs(checksum(NewID()))%21once for each outer row, which it may not always do (as you've already found out).
#Damien_The_Unbeliever explained why your query fails.
My first variant was not correct, because I didn't understand the problem in full.
You want to set each row in SERVICE_TICKET to a different random value from vehicle_typ.
To fix it simply order by random number, rather than comparing a random number with ID. Like this (and you don't care how many rows are in vehicle_typ as long as there is at least one row there).
WITH
CTE
AS
(
SELECT
dbo.SERVICE_TICKET.Vehicle_Type
CA.[text]
FROM
dbo.SERVICE_TICKET
CROSS APPLY
(
SELECT TOP 1 [text]
FROM dbo.vehicle_typ
ORDER BY NewID()
) AS CA
)
UPDATE CTE
SET Vehicle_Type = [text];
At first we make a Common Table Expression, you can think of it as a temporary table. For each row in SERVICE_TICKET we pick one random row from vehicle_typ using CROSS APPLY. Then we UPDATE the original table with chosen rows.
I have a table of +15 million rows and 36 columns, there are two rows of data for every object to which the table refers. I need to:
Move one Column 0 down one space so that the useful information from that column appears in the row below.
Here is a sample of the data with less columns:
Table name = ekd0310
I want to shift Column 0 down 1
Column 0 Column 1 Column 2 Column 3
B02100AA.CZE
B02100AA.CZF I MIGA0027 SUBDIREC.019
B02100AA.CZG
B02100AA.CZH I MIGA0027 SUBDIREC.019
B02100AA.CZI
B02100AA.CZJ I MIGA0027 SUBDIREC.019
B02100AA.CZK '
THe function that you are looking for is probably lead(). You can use this if you assume that there is a column that specifies the ordering. An example:
select e.*, lead(col) over (order by id) as nextcol
from ekd0310 e;
Although this is an ANSI standard function, not all databases support it (yet). You can do something similar with correlated subqueries. Similarly, the above returns the information, but it is possible to do this as an update as well.
I need to know if there is any way to have a SEQUENCE or something like that, as we have in Oracle. The idea is to get one number and then use it as a key to save some records in a table. Each time we need to save data in that table, first we get the next number from the sequence and then we use the same to save some records. Is not an IDENTITY column.
For example:
[ID] [SEQUENCE ID] [Code] [Value]
1 1 A 232
2 1 B 454
3 1 C 565
Next time someone needs to add records, the next SEQUENCE ID should be 2, is there any way to do it? the sequence could be a guid for me as well.
As Guillelon points out, the best way to do this in SQL Server is with an identity column.
You can simply define a column as being identity. When a new row is inserted, the identity is automatically incremented.
The difference is that the identity is updated on every row, not just some rows. To be honest, think this is a much better approach. Your example suggests that you are storing both an entity and detail in the same table.
The SequenceId should be the primary identity key in another table. This value can then be used for insertion into this table.
This can be done using multiple ways, Following is what I can think of
Creating a trigger and there by computing the possible value
Adding a computed column along with a function that retrieves the next value of the sequence
Here is an article that presents various solutions
One possible way is to do something like this:
-- Example 1
DECLARE #Var INT
SET #Var = Select Max(ID) + 1 From tbl;
INSERT INTO tbl VALUES (#var,'Record 1')
INSERT INTO tbl VALUES (#var,'Record 2')
INSERT INTO tbl VALUES (#var,'Record 3')
-- Example 2
INSERT INTO #temp VALUES (1,2)
INSERT INTO #temp VALUES (1,2)
INSERT INTO ActualTable (col1, col2, sequence)
SELECT temp.*, (SELECT MAX(ID) + 1 FROM ActualTable)
FROM #temp temp
-- Example 3
DECLARE #var int
INSERT INTO ActualTable (col1, col2, sequence) OUTPUT #var = inserted.sequence VALUES (1, 2, (SELECT MAX(ID) + 1 FROM ActualTable))
The first two examples rely on batch updating. But based on your comment, I have added example 3 which is a single input initially. You can then use the sequence that was inserted to insert the rest of the records. If you have never used an output, please reply in comments and I will expand further.
I would isolate all of the above inside of a transactions.
If you were using SQL Server 2012, you could use the SEQUENCE operator as shown here.
Forgive me if syntax errors, don't have SSMS installed
Using SQL Server 2008, have three tables, table a, table b and table c.
All have an ID column, but for table a and b the ID column is an identity integer, for table c the ID column is a varchar type
Currently a stored procedure take a name param, following certain logic, insert to table a or table b, get the identity, prefix with 'A' or 'B' then insert to table c.
Problem is, table C ID column potentially have the duplicated values, i.e. if identity from table A is 2, there might already have 'A2','A3','A5' in the ID column for table C, how to write a T-SQL query to identify the next available value in table C then ensure to update table A/B accordingly?
[Update]
this is the current step,
1. depends on input parameter, insert to table A or table B
2. initialize seed value = ##Identity
3. calculate ID value to insert to table C by prefix 'A' or append 'B' with the seed value
4. look for record match in table C by ID value from step 3, if didn't find any record, insert it, else increase seed value by 1 then repeat step 3
The issue being at a certain value range, there could be a huge block of value exists in table C ID, i.e. A3000 to A500000 existed now in table C ID, the database query is extemely slow if follow the existing logic. Needs to figure out a logic to smartly get the minimum available number (without the prefix)
it is hard to describe, hope this make more sense, I truly appreciate any help on this Thanks in advance!
This should do the trick. Simple self extracting example will work in SSMS. I even made it out of order just in case. You would just change your table to be where #Data is and then change Identifier field to replace 'ID'.
declare #Data Table ( Id varchar(3) );
insert into #Data values ('A5'),('A2'),('B1'),('A3'),('B2'),('A4'),('A1'),('A6');
With a as
(
Select
ID
, cast(right(Id, len(Id)-1) as int) as Pos
, left(Id, 1) as TableFrom
from #Data
)
select
TableFrom
, max(Pos) + 1 as NextNumberUp
from a
group by TableFrom
EDIT: If you want to not worry about production data you could add this last part amending what I wrote:
Select
TableFrom
, max(Pos) as LastPos
into #Temp
from a
group by TableFrom
select TableFrom, LastPos + 1
from #Temp
Regardless if this was production environment you are going to have to hit part of it at some time to get data. If the datasets are not too large and just varchar(256) or less and only 5 million rows or less you could dump that entire column from tableC to a temp table. Honestly query performance versus imports change vastly from system to system.
Following your design there shouldn't be any duplicates in Table C considering that A and B are unique.
A | B | C
1 1 A1
2 2 A2
B1
B2