My query is based on the following example
I have table say 'Table1'. Table1 has one row and one column. The name of the column is 'Column1'. 'Column1' is a text column (NVARCHAR). I have a comma separated keywords like 'key1,key2..keyn'. I want to search these keywords individually in the column1.
So in the where clause the query should be something like
SELECT ... FROM Table1
WHERE Column1 LIKE '%key1%'
AND Column1 LIKE '%key2%'
AND Column1 LIKE '%keyn%'
I just want to know how to write a query in a simplified manner. Table is quite small and performance is not a main concern.
Just declare the keywords in a variable for the test case
DECLARE #Keywords NVARCHAR(MAX)
SET #Keywords = 'Key1,Key2,Key3'
A simple example will be helpful to me.
This will be easier if you get these into table format. (Split Table Valued functions exist to do this to your delimited string - e.g. http://www.eggheadcafe.com/community/aspnet/13/10021854/fnsplit.aspx)
DECLARE #Keywords TABLE
(
COL NVARCHAR(100)
)
INSERT INTO #Keywords SELECT 'Key1' UNION ALL SELECT 'Key2' UNION ALL SELECT 'Key3'
SELECT ...
FROM Table1 c
JOIN #Keywords k ON c.Column1 LIKE '%' + k.COL + '%'
GROUP BY ...
HAVING COUNT(*) = (select COUNT(*) FROM #Keywords)
Related
I have an XML string:
<XML>
<xml_line>
<col1>1</col1>
<col2>foo 1</col2>
</xml_line>
<xml_line>
<col1>2</col1>
<col2>foo 2</col2>
</xml_line>
</XML>
I am extracting data from that string (stored in #data_xml) by storing it in SQL Server table and parsing it:
-- create temp table, insert XML string
CREATE TABLE table1 (data_xml XML)
INSERT table1
SELECT #data_xml
-- parse XML string into temp table
SELECT
N.C.value('col1[1]', 'int') col1_name,
N.C.value('col2[1]', 'varchar(31)') col2_name,
FROM
table1
CROSS APPLY
data_xml.nodes('//xml_line') N(C)
I would like to know if there is a generic way to accomplish the same without specifying column names (i.e. col1[1], col2[1])
You can use something like:
SELECT
N.C.value('let $i := . return count(//xml_line[. << $i]) + 1', 'int') as LineNumber,
Item.Node.value('local-name(.)', 'varchar(max)') name,
Item.Node.value('.', 'varchar(max)') value
FROM
table1
CROSS APPLY
data_xml.nodes('//xml_line') N(C)
CROSS APPLY
N.C.nodes('*') Item(Node)
To get:
LineNumber
name
value
1
col1
1
1
col2
foo 1
2
col1
2
2
col2
foo 2
See this db<>fiddle.
However, to spread columns horizontally, you will need to generate dynamic SQL after querying for distinct element names.
ADDENDUM: Here is an updated db<>fiddle that also shows a dynamic SQL example.
The above maps all values as VARCHAR(MAX). If you have NVARCHAR data you can make the appropriate changes. If you have a need to map specific columns to specific types, you will need to explicitly define and populate a name-to-type mapping table and incorporate that into the dynamic SQL logic. The same may be necessary if you prefer that the result columns be in a specific order.
ADDENDUM 2: This updated db<>fiddle now includes column type and ordering logic.
--------------------------------------------------
-- Extract column names
--------------------------------------------------
DECLARE #Names TABLE (name VARCHAR(100))
INSERT #Names
SELECT DISTINCT Item.Node.value('local-name(.)', 'varchar(max)')
FROM table1
CROSS APPLY data_xml.nodes('//xml_line/*') Item(Node)
--SELECT * FROM #Names
--------------------------------------------------
-- Define column-to-type mapping
--------------------------------------------------
DECLARE #ColumnTypeMap TABLE ( ColumnName SYSNAME, ColumnType SYSNAME, ColumnOrder INT)
INSERT #ColumnTypeMap
VALUES
('col1', 'int', 1),
('col2', 'varchar(10)', 2)
DECLARE #ColumnTypeDefault SYSNAME = 'varchar(max)'
--------------------------------------------------
-- Define SQL Templates
--------------------------------------------------
DECLARE #SelectItemTemplate VARCHAR(MAX) =
' , N.C.value(<colpath>, <coltype>) <colname>
'
DECLARE #SqlTemplate VARCHAR(MAX) =
'SELECT
N.C.value(''let $i := . return count(//xml_line[. << $i]) + 1'', ''int'') as LineNumber
<SelectItems>
FROM
table1
CROSS APPLY
data_xml.nodes(''//xml_line'') N(C)
'
--------------------------------------------------
-- Expand SQL templates into SQL
--------------------------------------------------
DECLARE #SelectItems VARCHAR(MAX) = (
SELECT STRING_AGG(SI.SelectItem, '')
WITHIN GROUP(ORDER BY ISNULL(T.ColumnOrder, 999), N.Name)
FROM #Names N
LEFT JOIN #ColumnTypeMap T ON T.ColumnName = N.name
CROSS APPLY (
SELECT SelectItem = REPLACE(REPLACE(REPLACE(
#SelectItemTemplate
, '<colpath>', QUOTENAME(N.name + '[1]', ''''))
, '<colname>', QUOTENAME(N.name))
, '<coltype>', QUOTENAME(ISNULL(T.ColumnType, #ColumnTypeDefault), ''''))
) SI(SelectItem)
)
DECLARE #Sql VARCHAR(MAX) = REPLACE(#SqlTemplate, '<SelectItems>', #SelectItems)
--------------------------------------------------
-- Execute
--------------------------------------------------
SELECT DynamicSql = #Sql
EXEC (#Sql)
Result (with some additional data):
LineNumber
col1
col2
bar
foo
1
1
foo 1
null
More
2
2
foo 2
Stuff
null
Is there any way to select all the columns except one in Snowflake like we have in bigquery:
select * except(columnname) from table
2022 update: Snowflake now supports EXCLUDE():
Test with:
with data as (
select 1 col_a, 2 col_b, 3 col_c, 4 col_d
)
select *, col_a as id
exclude (col_c, col_b, col_a)
from data
https://twitter.com/felipehoffa/status/1593311749100294144
Previous answer:
In lieu of the EXCEPT syntax, I wrote a stored procedure that can give you the list of columns to SELECT for:
create or replace procedure cols_except(table_name varchar, except varchar)
returns varchar
language sql as
begin
describe table identifier(:table_name);
return (
select listagg("name", ', ') cols_except
from table(result_scan(last_query_id()))
where not array_contains("name"::variant, (split(:except, ',')))
);
end;
You can use it to get the columns to select for, after eliminating the values that match the except clause:
call cols_except('snowflake_sample_data.tpch_sf1.nation', 'N_NAME,N_REGIONKEY');
Snowflake supports natively SELECT * EXCLUDE(<col_list>) syntax:
SELECT * EXCLUDE id FROM tab1;
SELECT * EXCLUDE (id, col1) FROM tab1;
For sample data:
CREATE OR REPLACE TABLE tab1(id INT, col1 TEXT, col2 TEXT)
AS
SELECT 1, 'a', 'b';
Output:
I have a schema in my SQL table out of which some table has a time value stamp (same column name 'timestamp' in all the tables in the schema) and I need to create a new table which will give the latest time stamp for each such table. I have achieved a part which will give me a table with 2 columns, one the table name column and another column which gives the query for each table which if runs will give me the latest timeStamp for each table in table name Column. The script I used is as follows and I show 3 rows as an example:
WITH CTE AS
(
SELECT
CONCAT(schema_name(t.schema_id), '.',t.name) AS table_name,
c.name AS 'time_stamp'
FROM
sys.tables t
INNER JOIN
sys.columns c ON c.object_id = t.object_id
WHERE
schema_name(t.schema_id) = 'PROD'
AND c.name = 'timestamp'
)
SELECT table_name, time_stamp
INTO #TEMP_TABLE
FROM CTE
DECLARE #i int = 1, #c int = (SELECT COUNT(*) FROM #TEMP_TABLE)
DECLARE #Result TABLE
(
tName varchar(500),
tStamp varchar(500)
)
WHILE (#i <= #c)
BEGIN
INSERT INTO #Result
SELECT
table_name,
'SELECT MAX('+ time_stamp +') FROM ' + table_name
FROM #TEMP_TABLE;
SET #i = #i + 1
END
DROP TABLE #TEMP_TABLE
SELECT * FROM #RESULT
When I run this script I get the following table (3 rows shown as an illustration)
My output (O)
tName tStamp
-----------------------------------------------------------
PROD.table_A SELECT MAX(time_stamp) FROM PROD.table_A
PROD.table_B SELECT MAX(time_stamp) FROM PROD.table_B
PROD.table_C SELECT MAX(time_stamp) FROM PROD.table_C
However what I want is the value of the query in the tStamp column and not the query string. So actually the output table should look like (say assuming the query in each of the above rows in column tStamp. I put in some max values as an example when we run each query in tStamp column)
My final expected output (F)
tName tStamp
------------------------------------------
PROD.table_A 2021-10-12 14:20:56.000
PROD.table_B 2021-11-01 19:04:35.000
PROD.table_C 2021-10-23 08:07:12.000
I am in a limbo at this stage not sure, how to get the table F from table O. So I will really appreciate any help. If it can be possible to tweak something which I am doing to get directly the output table F or if we can work on the table O to get to table F anything can help.
Thanks in advance.
If this is a one shot thing, I would consider just using a macro (vim, excel) to generate the query text for each table using your CTE results and then paste it back in and run.
If not, you could consider some of the suggestions for dynamic sql in this article: [https://www.mssqltips.com/sqlservertip/1160/execute-dynamic-sql-commands-in-sql-server/][1]
I'm trying to accumulate values into a variable in SQL Server>=2012.
It works in case 1 below, but in case 2 I get the answer ",CD" instead of the expected ",EF,AB,CD" Why?
In MMS:
USE MyDB
GO
-- Create a simple table
CREATE TABLE Tbl1 (Code VARCHAR(2), So TINYINT NULL)
INSERT INTO Tbl1 VALUES('AB', 10)
INSERT INTO Tbl1 VALUES('CD', NULL)
INSERT INTO Tbl1 VALUES('EF', 5)
GO
-- Case 1
DECLARE #MyVar VARCHAR(255) = ''
SELECT #MyVar=#MyVar + ',' + Code FROM Tbl1 ORDER BY So
SELECT #MyVar
GO
-- Case 2
DECLARE #MyVar VARCHAR(255) = ''
SELECT #MyVar=#MyVar + ',' + Code FROM Tbl1 ORDER BY ISNULL(So, 255)
SELECT #MyVar
GO
The explanation is in the documentation:
Don't use a variable in a SELECT statement to concatenate values (that
is, to compute aggregate values). Unexpected query results may occur.
Because, all expressions in the SELECT list (including assignments)
aren't necessarily run exactly once for each output row.
There are opinions (but not in the official docs), stating that without an ORDER BY clause (and/or a DISTINCT clause) the aggregation works as you expect.
If you are using SQL Server 2017+, you may use STRING_AGG() to build the expected output:
DECLARE #MyVar VARCHAR(255) = ''
SELECT #MyVar = STRING_AGG(Code, ',') WITHIN GROUP (ORDER BY ISNULL(So, 255))
FROM Tbl1
SELECT #MyVar
The problem that I need to resolve is data transfer from one table with many dynamic fields into other structured key value table.
The first table comes from a data export from another system, and has the following structure ( it can have any column name and data):
[UserID],[FirstName],[LastName],[Email],[How was your day],[Would you like to receive weekly newsletter],[Confirm that you are 18+] ...
The second table is where I want to put the data, and it has the following structure:
[UserID uniqueidentifier],[QuestionText nvarchar(500)],[Question Answer nvarchar(max)]
I saw many examples showing how to unpivot table, but my problem is that I dont know what columns the Table 1 will have. Can I somehow dynamically unpivot the first table,so no matter what columns it has, it is converted into a key-value structure and import the data into the second table.
I will really appreciate your help with this.
You can't pivot or unpivot in one query without knowing the columns.
What you can do, assuming you have privileges, is query sys.columns to get the field names of your source table then build an unpivot query dynamically.
--Source table
create table MyTable (
id int,
Field1 nvarchar(10),
Field2 nvarchar(10),
Field3 nvarchar(10)
);
insert into MyTable (id, Field1, Field2, Field3) values ( 1, 'aaa', 'bbb', 'ccc' );
insert into MyTable (id, Field1, Field2, Field3) values ( 2, 'eee', 'fff', 'ggg' );
insert into MyTable (id, Field1, Field2, Field3) values ( 3, 'hhh', 'iii', 'jjj' );
--key/value table
create table MyValuesTable (
id int,
[field] sysname,
[value] nvarchar(10)
);
declare #columnString nvarchar(max)
--This recursive CTE examines the source table's columns excluding
--the 'id' column explicitly and builds a string of column names
--like so: '[Field1], [Field2], [Field3]'.
;with columnNames as (
select column_id, name
from sys.columns
where object_id = object_id('MyTable','U')
and name <> 'id'
),
columnString (id, string) as (
select
2, cast('' as nvarchar(max))
union all
select
b.id + 1, b.string + case when b.string = '' then '' else ', ' end + '[' + a.name + ']'
from
columnNames a
join columnString b on b.id = a.column_id
)
select top 1 #columnString = string from columnString order by id desc
--Now I build a query around the column names which unpivots the source and inserts into the key/value table.
declare #sql nvarchar(max)
set #sql = '
insert MyValuestable
select id, field, value
from
(select * from MyTable) b
unpivot
(value for field in (' + #columnString + ')) as unpvt'
--Query's ready to run.
exec (#sql)
select * from MyValuesTable
In case you're getting your source data from a stored procedure, you can use OPENROWSET to get the data into a table, then examine that table's column names. This link shows how to do that part.
https://stackoverflow.com/a/1228165/300242
Final note: If you use a temporary table, remember that you get the column names from tempdb.sys.columns like so:
select column_id, name
from tempdb.sys.columns
where object_id = object_id('tempdb..#MyTable','U')