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The Sqlite Oracle Compatibility Functions is an experimental compatibility layer for SQLite vs Oracle, written in Python 3.
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Sometimes you need to remove nasty duplicate on a table, based on a subset of the column. On every big database there is something called “rowid” which can be used to indentify a column in a unique way. On PostgreSQL is called ctid, as we shall see:
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Disapprove with me!Okey, you know Oracle. A very good database, a very old database, a very solid rock. Not famous for its error messages. I have already stumbled upon a misleading error on the old rock.
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I stumbled upon a very brain-f**k error on Oracle 10g on these days.
Context: the following query [sql]SELECT * FROM (
SELECT TO_NUMBER(CUSTOMER_ID) AS SNDG FROM BAD_CODES_TABLE WHERE
AND I_LIKE=UPPER(‘STATIC_CONDITION’) AND CUSTOMER_ID NOT LIKE ‘%P%’ ) S WHERE TO_NUMBER(S.SNDG) >2000[/sql] could trigger a Invalid number if CUSTOMER_ID column contains invalid numbers.Why?
Well…if you ask to “explain plan”, you will get something like
- a table full scan
- Filter Predicates AND
- I_LIKE=UPPER('STATIC_CONDITION')
- TO_NUMBER(S.SNDG) >2000
- CUSTOMER_ID NOT LIKE '%P%'
- Filter Predicates AND
Read More - a table full scan
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Come evitare iniezione SQL: lato SQL Server (SP_EXECUTESQL)
In generale va evitato nel modo più assoluto la scrittura di query sql diamiche.Va evitato cioè l’uso lato SQL Server di sp_executesql e EXEC
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