sql multiple concatenation in a string - string

I have a big problem that I don't understand.
I have this query in Tsql :
SET #sSQL = 'SELECT *
INTO '+#sTableValeursDefaut+'
FROM OPENQUERY(LINKSVR_LOCAL , '' SET FMTONLY OFF
EXEC [AIGP].[dbo].[rp_WEB_ValeursDefaut_Get]
'''''+'sds'+''''',
'+ISNULL(CONVERT(VARCHAR, #fkIDProjet), 'NULL+')+',
'+'123'+''')'
EXEC(#sSQL)
This work perfectly. But when I change the '123' for CONVERT(VARCHAR, #fkIDCfgFormulaire) and the 'sds' to #sNoUsager the query don't work !
SET #sSQL = 'SELECT *
INTO '+#sTableValeursDefaut+'
FROM OPENQUERY(LINKSVR_LOCAL , '' SET FMTONLY OFF
EXEC [AIGP].[dbo].[rp_WEB_ValeursDefaut_Get]
'''''+#sNoUsager+''''',
'+ISNULL(CONVERT(VARCHAR, #fkIDProjet), 'NULL+')+',
'+CONVERT(VARCHAR, #fkIDCfgFormulaire)+''')'
EXEC(#sSQL)
What I am doing wrong ?

Without more information it's difficult to tell. Could be anything from the datatypes of the variables to the value of the variables you are passing...
We could do with some test data please.
It may also be that you have a '+' character in your literal I haven't tested it but 'NULL+' should probably read 'NULL'
Or it could be because in your CONVERT(VARCHAR, #fkIDProjet) you don't give a length to your varchar try something like this instead CONVERT(VARCHAR(5), #fkIDProjet)

Related

Update multiple column with bind variable using cx_Oracle.executemany()

I have been trying to update some columns of a database table using cx_Oracle in Python. I created a list named check_to_process which is a result of another sql query. I am creating log_msg in the program based on success or failure and want to update same in the table only for records in check_to_process list. When I update the table without using bind variable <MESSAGE = %s>, it works fine. But when I try to use bind variable to update the columns it gives me error :
cursor.executemany("UPDATE apps.SLCAP_CITI_PAYMENT_BATCH SET MESSAGE = %s, "
TypeError: an integer is required (got type str)
Below is the code, I am using:
import cx_Oracle
connection = cx_Oracle.connect(user=os.environ['ORA_DB_USR'], password=os.environ['ORA_DB_PWD'], dsn=os.environ['ORA_DSN'])
cursor = connection.cursor()
check_to_process = ['ACHRMUS-20-OCT-2021 00:12:57', 'ACHRMUS-12-OCT-2021 16:12:01']
placeholders = ','.join(":x%d" % i for i,_ in enumerate(check_to_process))
log_msg = 'Success'
cursor.executemany("UPDATE apps.SLCAP_CITI_PAYMENT_BATCH SET MESSAGE = %s, "
"PAYMENT_FILE_CREATED_FLAG='N' "
"WHERE PAYMENT_BATCH_NAME = :1",
[(i,) for i in check_to_process], log_msg, arraydmlrowcounts=True)
Many thanks for suggestions and insights!
Your code has an odd mix of string substitution (the %s) and bind variable placeholders (the :1). And odd code that creates bind variable placeholders that aren't used. Passing log_msg the way you do isn't going to work, since executemany() syntax doesn't support string substitution.
You probably want to use some kind of IN list, as shown in the cx_Oracle documentation Binding Multiple Values to a SQL WHERE IN Clause. Various solutions are shown there, depending on the number of values and frequency that the statement will be re-executed.
Use only bind variables. You should be able to use execute() instead of executemany(). Effectively you would do:
cursor.execute("""UPDATE apps.SLCAP_CITI_PAYMENT_BATCH
SET MESSAGE = :1
WHERE PAYMENT_BATCH_NAME IN (something goes here - see the doc)""",
bind_values)
The bottom line is: read the documentation and review examples like batch_errors.py. If you still have problems, refine your question, correct it, and add more detail.

Pass in SQL query the table name as parameter

A possible solution for this question is here:
https://stackoverflow.com/a/6223961/12343395
It will probably work with a lot of work around.
But I have stored my table names in string format and want to call them as needed.
I am using Pandas read_sql_query. So as in params, I am passing, the table name and a few parameters in the WHERE section.
The WHERE section is fine, since the parameters are originally strings. But in the FROM section,
I really want the schema.table as a non-string.
Here is a snippet.
SELECT "rainfall(mm)","tmin(C)","tmax(C)","TimeStamp"
FROM crop_tables[choose_crop][0]
WHERE "District_Name" = %s AND "Season" = %s
ORDER BY "TimeStamp" ASC
where crop_tables[choose_crop][0] is 'sagita_historic.soyabean_daily_analyses' in this case.
But FROM will throw an error since it doesn't accept strings. So in essence, I wish to strip the 'sagita_historic.soyabean_daily_analyses' as a non-string.
Is it possible to do so?
Thank you.
Not sure I fully understand but maybe this will do?
SELECT "rainfall(mm)","tmin(C)","tmax(C)","TimeStamp"
FROM f"{crop_tables[choose_crop][0]}"
WHERE "District_Name" = %s AND "Season" = %s
ORDER BY "TimeStamp" ASC

when I shoud use format() function and str() function. which one is better?

I am stuck to find out better one between str() and format() in python
"SELECT schools.deis_income , schools.school_name,SUM(money.coin_in_amount) AS coinamount, SUM(money.note_in_amount) AS noteamount , SUM(money.coffee_coin_in_amount) AS coffeeamount , SUM(money.coin_out_amount) AS coinoutamount, SUM(money.note_out_amount) AS noteoutamount FROM money_transactions AS money JOIN school_admin_details AS sa on sa.id = money.school_admin_id JOIN schools ON schools.id=sa.school_id WHERE sa.school_id ={school_id} AND money.transaction_time BETWEEN '{start_date}' AND '{end_date}' GROUP BY schools.id".format(school_id=school_id,start_date=start_date,end_date=end_date)
I use format function here. can I use str() ?
please tell me which one give me quick result, str() or format() ???
If your question is which of this:
foo = "some text " + str(some_var) + " and some other text"
or this:
foo = "some text {} and some other text".format(var)
is "better", the general consensus is very clear: string formatting is much easier to read and maintain and the one pythonic way to go.
Now for your particular example, the answer is that both are totally wrong - unless you're ok to give full access to your database to even the most inept script kiddie. For SQL queries, the proper solution is to use prepared statements, where your db connector will take care of proper formatting and sanitizing of the values:
# assumes MySQL - for other vendors check your own
# db-api connector's doc for the correct placeholder
query = "SELECT somefield FROM mytable where somedate > %(somedate)s and something_else = %(someval)s"
cursor.execute(query, {"somedate": some_date, "someval": 42})

Condition IF In Power Query's Advanced Editor

I have a field named field, and I would like to see if it is null, but I get an error in the query, my code is this:
let
Condition= Excel.CurrentWorkbook(){[Name="test_table"]}[Content],
field= Condition{0}[fieldColumn],
query1="select * from students",
if field <> null then query1=query1 & " where id = '"& field &"',
exec= Oracle.Database("TESTING",[Query=query1])
in
exec
but I get an error in the condition, do you identify the mistake?
I got Expression.SyntaxError: Token Identifier expected.
You need to assign the if line to a variable. Each M line needs to start with an assignment:
let
Condition= Excel.CurrentWorkbook(){[Name="test_table"]}[Content],
field= Condition{0}[fieldColumn],
query1="select * from students",
query2 = if field <> null then query1 & " some stuff" else " some other stuff",
exec= Oracle.Database("TESTING",[Query=query2])
in
exec
In query2 you can build the select statement. I simplified it, because you also have conflicts with the double quotes.
I think you're looking for:
if Not IsNull(field) then ....
Some data types you may have to check using IsEmpty() or 'field is Not Nothing' too. Depending on the datatype and what you are using.
To troubleshoot, it's best to try to set a breakpoint and locate where the error is happening and watch the variable to prevent against that specific value.
To meet this requirement, I would build a fresh Query using the PQ UI to select the students table/view from Oracle, and then use the UI to Filter the [id] column on any value.
Then in the advanced editor I would edit the generated FilteredRows line using code from your Condition + field steps, e.g.
FilteredRows = Table.SelectRows(TESTING_students, each [id] = Excel.CurrentWorkbook(){[Name="test_table"]}{0}[fieldColumn])
This is a minor change from a generated script, rather than trying to write the whole thing from scratch.

Substitute member of variable within string in Powershell

I have the following string expression in a PowerShell script:
"select count(*) cnt from ${schema}.${table} where ${col.column_name} is null"
The schema and table resolve to the values of $schema and $table, respectively. However, an empty string is supplied for ${col.column_name}. How can I dot into the member of a variable as part of a string substitution?
How about:
"select count(*) cnt from $schema.$table where $($col.column_name) is null"
I think the problem you're having is mainly syntax related. If you have a variable named $foo, ${foo} references the same variable. So, the ${table} and ${schema} references in your sql string work ok.
The issue is with ${col.column_name}. Your variable (I assume) is called $col, and has a member named column_name. As Robert and Steven both indicate in their answers, to refer to this, you should use $($col.column_name). In general, $(expression) will be replaced with the value of the expression.
The reason for allowing braces in variable names is so that variables can have unusual characters in their names. I would recommend not using the ${} syntax (unless you have a compelling reason), and replacing it with straight $var references for variables and $($var.member) for member references in strings.
One way would be:
"select count(*) cnt from $schema.$table where $($col.column_name) is null"
Another option would be
"select count(*) cnt from {0}.{1} where {2} is null" -f $schema, $table, $col.column_name

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