Patch to 6.6.6 fixing single quote becoming \047

Code patches written by our users to solve certain "problems" that were not solved, yet.

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cnliou
Zeos Dev Team
Zeos Dev Team
Posts: 31
Joined: 11.11.2005, 12:18

Patch to 6.6.6 fixing single quote becoming \047

Postby cnliou » 10.05.2013, 09:57

Newer versions of PostgreSQL appears to handle escape syntax differently from older ones. Version 9.2 takes literals like these two SQL text:

INSERT INTO t1 VALUES (E'This is Jim\'s home.')

INSERT INTO t1 VALUES (E'This is Jim\047s home.')

Take special note on the prefixing character "E"!
Without the leading 'E' like the following SQL text

INSERT INTO t1 VALUES ('This is Jim\047s home.')

saves

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This is Jim\047s home.
in t1.c1. This is exactly the symptom reported at: http://zeos.firmos.at/viewtopic.php?t=3745&sid=6642e4facee5d88425c8a6d62046a3cc

This file simply adds a leading 'E' to literal strings containing any occurrence of characters \0, \, and '.

Only

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function EncodeString(CharactersetCode: TZPgCharactersetType; Value: string): string;
is modified. I leave

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function EncodeString(Value: string): string;
as is because I suspect it is obsolete.

Perhaps

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function EncodeBinaryString(Value: string): string;
in version 6.6.6 and

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function PGEscapeString(Handle: Pointer; const Value: ZAnsiString;
    ConSettings: PZConSettings; WasEncoded: Boolean = False): ZAnsiString;
in version 7.1 also need the similar revision.

I am not sure setting standard_conforming_strings (boolean) in postgresql.conf to off is a quick and dirty fix to this issue.

Furthuer, perhaps the best approach is revising functions EncodingString() in v 6.6.6 and PGEscapeString and v7.1 to call the new escape functions supported by newer libpq instead:

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char *PQescapeLiteral(PGconn *conn, const char *str, size_t length);

char *PQescapeIdentifier(PGconn *conn, const char *str, size_t length);

size_t PQescapeStringConn(PGconn *conn, char *to, const char *from, size_t length, int *error);
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