Export Postgres queries to the same excel file - excel

I know I could copy a query to a csv file using:
COPY (
SELECT * FROM my_table
) TO '/tmp/myfile.csv' CSV HEADER DELIMITER E'\t';
But I need to export multiple queries to the same csv file, like:
COPY (
(SELECT * FROM my_table) AS tab1
(SELECT * FROM my_table2) AS tab2
(SELECT * FROM my_table3) AS tab3
(SELECT * FROM my_table4) AS tabN
) TO '/tmp/myfile.csv' CSV HEADER DELIMITER E'\t';
Is there a way of doing that?

You can do a union on all the select statements as long as you select the same column types from each, like so. If cola and colc are not the same type, cast it to the same type. If you have fewer fields, select a static value such as 0, NULL, or something like that.
COPY (
(SELECT cola, colb FROM my_table1) AS tab1
UNION ALL
(SELECT colc, cold FROM my_table2) AS tab2
) TO '/tmp/myfile.csv' CSV HEADER DELIMITER E'\t';
Alternatively, you could do the export to 2 files and combine them. Use your code to export to /tmp/myfile1.csv and /tmp/myfile2.csv
Then:
cat /tmp/myfile1.csv /tmp/myfile2.csv >/tmp/combined.csv

Related

How to get top 3 columns and their values across multiple columns (dynamically) in BigQuery

I have a table that looks like this
select 'Alice' AS ID, 1 as col1, 3 as col2, -2 as col3, 9 as col4
union all
select 'Bob' AS ID, -9 as col1, 2 as col2, 5 as col3, -6 as col4
I would like to get the top 3 absolute values for each record across the four columns and then format the output as a dictionary or STRUCT like below
select
'Alice' AS ID, [STRUCT('col4' AS column, 9 AS value), STRUCT('col2',3), STRUCT('col3',-2)] output
union all
select
'Bob' AS ID, [STRUCT('col1' AS column, -9 AS value), STRUCT('col4',-6), STRUCT('col3',5)]
output
output
I would like it to be dynamic, so avoid writing out columns individually. It could go up to 100 columns that change
For more context, I am trying to get the top three features from the batch local explanations output in Vertex AI
https://cloud.google.com/vertex-ai/docs/tabular-data/classification-regression/get-batch-predictions
I have looked up some examples, would like something similar to the second answer here How to get max value of column values in a record ? (BigQuery)
EDIT: the data is actually structured like this. If this can be worked with more easily, this would be a better option to work from
select 'Alice' AS ID, STRUCT(1 as col1, 3 as col2, -2 as col3, 9 as col4) AS featureAttributions
union all
SELECT 'Bob' AS ID, STRUCT(-9 as col1, 2 as col2, 5 as col3, -6 as col4) AS featureAttributions
Consider below query.
SELECT ID, ARRAY_AGG(STRUCT(column, value) ORDER BY ABS(value) DESC LIMIT 3) output
FROM (
SELECT * FROM sample_table UNPIVOT (value FOR column IN (col1, col2, col3, col4))
)
GROUP BY ID;
Query results
Dynamic Query
I would like it to be dynamic, so avoid writing out columns individually
You need to consider a dynamic SQL for this. By refering to the answer from #Mikhail you linked in the post, you can write a dynamic query like below.
EXECUTE IMMEDIATE FORMAT("""
SELECT ID, ARRAY_AGG(STRUCT(column, value) ORDER BY ABS(value) DESC LIMIT 3) output
FROM (
SELECT * FROM sample_table UNPIVOT (value FOR column IN (%s))
)
GROUP BY ID
""", ARRAY_TO_STRING(
REGEXP_EXTRACT_ALL(TO_JSON_STRING((SELECT AS STRUCT * EXCEPT (ID) FROM sample_table LIMIT 1)), r'"([^,{]+)":'), ',')
);
For updated sample table
SELECT ID, ARRAY_AGG(STRUCT(column, value) ORDER BY ABS(value) DESC LIMIT 3) output
FROM (
SELECT * FROM (SELECT ID, featureAttributions.* FROM sample_table)
UNPIVOT (value FOR column IN (col1, col2, col3, col4))
)
GROUP BY ID;
EXECUTE IMMEDIATE FORMAT("""
SELECT ID, ARRAY_AGG(STRUCT(column, value) ORDER BY ABS(value) DESC LIMIT 3) output
FROM (
SELECT * FROM (SELECT ID, featureAttributions.* FROM sample_table)
UNPIVOT (value FOR column IN (%s))
)
GROUP BY ID
""", ARRAY_TO_STRING(
REGEXP_EXTRACT_ALL(TO_JSON_STRING((SELECT featureAttributions FROM sample_table LIMIT 1)), r'"([^,{]+)":'), ',')
);

Rename a file column name in Azure Synapse

I have a file with poor naming convention I would like to clean up before using in Azure Synapse. Is it possible to rename the column in the with block?
SELECT TOP 10 *
FROM OPENROWSET(
BULK 'path_to_file.csv'
FORMAT = 'CSV'
PARSER_VERSION = '2.0'
FIRSTROW = 2)
WITH (
[ORDER ID] varchar(50)
) as rows
I could use an alias in the select but was hoping to clean it up before that.
SELECT [ORDER ID] as order_id
And I could wrap this in a view - just was hoping there's a way to rename earlier.
Yes, it is possible to rename columns in WITH block; the name you provide there will override the column name read from the file (even with HEADER_ROW set to TRUE.
There's a caveat though. You will have to either provide names for all of your columns:
SELECT TOP 10 *
FROM OPENROWSET
(BULK 'path_to_file.csv',
FORMAT = 'CSV',
PARSER_VERSION = '2.0',
HEADER_ROW = true)
WITH
(
your_column_name_1 varchar(50)
...
your_column_name_N varchar(50)
)
AS rows
...or pick the ones you want to keep and/or rename using their ordinal number:
SELECT TOP 10 *
FROM OPENROWSET
(BULK 'path_to_file.csv',
FORMAT = 'CSV',
PARSER_VERSION = '2.0',
HEADER_ROW = true)
WITH
(
your_column_name_1 varchar(50) 1
your_column_name_4 varchar(50) 4
)
AS rows
You can also override the names with a subquery / derived table, eg
SELECT *
FROM (
SELECT TOP 100 *
FROM OPENROWSET (
BULK 'some path',
FORMAT = 'CSV',
PARSER_VERSION ='2.0',
FIRSTROW = 2
) AS [result]
) x ( col1, col2 )
This is more compact than the WITH clause I think, where you have to specify all columns, all data-types and all ordinals as far as I can tell. Unfortunately it won't let you put the column list after the [result] alias.

How to use a variable in place of column names when doing select in Pyspark/Sparksql

I have a variable with column names in it, like below:
VAR=Fullname,Address,DOB
I need to pass this variable in my spark sql instead of column names like below:
spark.sql("""
Select
VAR
From mytable
where 1=1
#some additional filters
""")
so it is treated as if I was giving the column names explicitly like below:
spark.sql("""
Select
Fullname
,Address
,DOB
From mytable
where 1=1
#some additional filters
""")
how can this be implemented using pyspark/sparksql
Below is code sample in pyspark for same,
var = 'Fullname,Address,DOB'
query = "SELECT {} FROM From mytable WHERE 1=1 #additional filters".format(var)
spark.sql(query)

WHERE variable = ( subquery ) in OpenSQL

I'm trying to retrieve rows from a table where a subquery matches an variable. However, it seems as if the WHERE clause only lets me compare fields of the selected tables against a constant, variable or subquery.
I would expect to write something like this:
DATA(lv_expected_lines) = 5.
SELECT partner contract_account
INTO TABLE lt_bp_ca
FROM table1 AS tab1
WHERE lv_expected_lines = (
SELECT COUNT(*)
FROM table2
WHERE partner = tab1~partner
AND contract_account = tab1~contract_account ).
But obviously this select treats my local variable as a field name and it gives me the error "Unknown column name "lv_expected_lines" until runtime, you cannot specify a field list."
But in standard SQL this is perfectly possible:
SELECT PARTNER, CONTRACT_ACCOUNT
FROM TABLE1 AS TAB1
WHERE 5 = (
SELECT COUNT(*)
FROM TABLE2
WHERE PARTNER = TAB1.PARTNER
AND CONTRACT_ACCOUNT = TAB1.CONTRACT_ACCOUNT );
So how can I replicate this logic in RSQL / Open SQL?
If there's no way I'll probably just write native SQL and be done with it.
The program below might lead you to an Open SQL solution. It uses the SAP demo tables to determines the plane types that are used on a specific number of flights.
REPORT zgertest_sub_query.
DATA: lt_planetypes TYPE STANDARD TABLE OF s_planetpp.
PARAMETERS: p_numf TYPE i DEFAULT 62.
START-OF-SELECTION.
SELECT planetype
INTO TABLE lt_planetypes
FROM sflight
GROUP BY planetype
HAVING COUNT( * ) EQ p_numf.
LOOP AT lt_planetypes INTO DATA(planetype).
WRITE: / planetype.
ENDLOOP.
It only works if you don't need to read fields from TAB1. If you do you will have to gather these with other selects while looping at your results.
For those dudes who found this question in 2020 I report that this construction is supported since ABAP 7.50. No workarounds are needed:
SELECT kunnr, vkorg
FROM vbak AS v
WHERE 5 = ( SELECT COUNT(*)
FROM vbap
WHERE kunnr = v~kunnr
AND vkorg = v~vkorg )
INTO TABLE #DATA(customers).
This select all customers who made 5 sales orders within some sales organization.
In ABAP there is no way to do the query as in NATIVE SQL.
I would advice not to use NATIVE SQL, instead give a try to SELECT/ENDSELECT statement.
DATA: ls_table1 type table1,
lt_table1 type table of table1,
lv_count type i.
SELECT PARTNER, CONTRACT_ACCOUNT
INTO ls_table1
FROM TABLE1.
SELECT COUNT(*)
INTO lv_count
FROM TABLE2
WHERE PARTNER = TAB1.PARTNER
AND CONTRACT_ACCOUNT = TAB1.CONTRACT_ACCOUNT.
CHECK lv_count EQ 5.
APPEND ls_table1 TO lt_table1.
ENDSELECT
Here you append to ls_table1 only those rows where count is equals to 5 in selection of table2.
Hope it helps.

how to join two or more tables and result set having all distinct values

I have some 20 excel files containing data. all the tables have same columns like id name age location etc..... each file has distinct data but i don't know if data in one file is again repeated in another file. so i want to join all the files and the result st should contain distinct values. please help me out with this problem as soon as possible. i want the result set to be stored in an access database.
I would recomend either linking the sheets in acces, or importing the sheets as tabels.
Then from there try to determine using a DISTINCT select from the tables/sheets the keys required, and only selecting the records as required.
In SQL, you can use JOIN or NATURAL JOIN to join tables. I would look into NATURAL JOIN since you said all tables have the same values.
After that you can use DISTINCT to get distinct values.
I'm not sure if this is what you're looking for though: your question asks about excel but you've tagged it with SQL.
If you can use all the tables in one query, you can use a union to get the distinct rows:
select id, name, age, location from Table1
union
select id, name, age, location from Table2
union
select id, name, age, location from Table3
union
...
You can insert the records directly from the result:
insert into ResultTable
select id, name, age, location from Table1
union
....
If you only can select from one table at a time, you can skip the insert of rows that are already in the table:
insert into ResultTable
select t.id, t.name, t.age, t.location from Table1 as t
left join ResultTable as r on r.id = t.id
where r.id is null
(Assuming that id is a unique field identifying the record.)
It seems the unique set of data you want is this:
SELECT T1.name, T1.loc
FROM [Excel 8.0;HDR=YES;IMEX=1;DATABASE=C:\db1.xls;
].[Sheet1$] AS T1
UNION
SELECT T1.name, T1.loc
FROM [Excel 8.0;HDR=YES;IMEX=1;DATABASE=C:\db2.xls;
].[Sheet1$] AS T1
...but that you then want to arbitrarily apply a sequence of integers as id (rather than using the id values from the Excel tables).
Because Access Database Engine does not support common table expressions and Excel does not support VIEWs, you will have to repeat that UNION query as derived tables (hopefully the optimizer will recognize the repeat?) e.g. using a correlated subquery to get the row number:
SELECT (
SELECT COUNT(*) + 1
FROM (
SELECT T1.name, T1.loc
FROM [Excel 8.0;HDR=YES;IMEX=1;DATABASE=C:\db1.xls;
].[Sheet1$] AS T1
UNION
SELECT T1.name, T1.loc
FROM [Excel 8.0;HDR=YES;IMEX=1;DATABASE=C:\db2.xls;
].[Sheet1$] AS T1
) AS DT1
WHERE DT1.name < DT2.name
) AS id,
DT2.name, DT2.loc
FROM (
SELECT T2.name, T2.loc
FROM [Excel 8.0;HDR=YES;IMEX=1;DATABASE=C:\db1.xls;
].[Sheet1$] AS T2
UNION
SELECT T2.name, T2.loc
FROM [Excel 8.0;HDR=YES;IMEX=1;DATABASE=C:\db2.xls;
].[Sheet1$] AS T2
) AS DT2;
Note:
i want the result set to be stored in
an access database
Then maybe you should migrate the Excel data into a staging table in your Access database and do the data scrubbing from there. At least you could put that derived table into a VIEW :)
Join is to combine two tables by matching the values in corresponding columns. In result, you will get a merged table which consists of the first table, plus the matched rows copied from the second table. You can use DIGBD add-in for excel

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