Postgresql — Ansi Odbc [2021]

PostgreSQL Unicode(x64) PostgreSQL ANSI(x64) | Parameter | Recommended Value | Why | |-----------|------------------|-----| | Client Encoding | Leave blank or set to your ANSI code page name (e.g., WIN1252 , WIN1251 , SJIS ) | Overrides automatic detection. If wrong, data corruption occurs. | | Server Encoding | UTF8 | PostgreSQL default. The driver expects UTF-8 on the wire. | | Use Declare/Fetch | 1 (enabled) | Important for large result sets – forces server-side cursors. | | Bytea as LongVarBinary | 1 | Prevents accidental ANSI conversion of binary data. | | True is -1 | As needed for legacy VB (False=0, True=-1) | Affects boolean conversion. | Example Connection String (ANSI mode) DRIVER=PostgreSQL ANSI(x64); SERVER=192.168.1.100; PORT=5432; DATABASE=legacy_db; UID=appuser; PWD=secret; ClientEncoding=WIN1252; UseDeclareFetch=1; 5. Common Pitfalls and Troubleshooting Pitfall 1: Data Truncation or Garbled Text Symptom : Étienne becomes ?tienne or Étienne . Cause : Mismatch between application's ANSI code page and the ClientEncoding DSN setting. Fix : Determine the application's code page (e.g., by checking system locale). On Windows, run chcp in the app's environment. Set ClientEncoding accordingly. Pitfall 2: SQLDriverConnect Returns IM014 (Invalid connection string attribute) Cause : Using SQL_DRIVER_NOPROMPT with an ANSI driver but passing Unicode connection string buffers. Fix : Ensure all strings passed to SQLDriverConnect are SQLCHAR* , not SQLWCHAR* . Pitfall 3: ERROR: invalid byte sequence for encoding "UTF8": 0x80 Cause : Application sent a raw binary byte (e.g., 0x80) that is invalid in UTF-8. The ANSI-to-UTF8 conversion failed. Fix : Check that the application is not embedding binary data in text fields. Use BYTEA for binary. Pitfall 4: Double Byte Character Corruption (e.g., Chinese, Japanese) Symptom : Inserting "漢字" results in "姉帤" or random characters. Cause : The ANSI driver treats each byte independently. Shift-JIS or GB18030 multi-byte sequences are broken. Fix : Do not use ANSI driver for CJK. Switch to Unicode ODBC driver immediately. 6. Performance Considerations | Aspect | ANSI Driver | Unicode Driver | |--------|-------------|----------------| | Per-row conversion overhead | Yes – every column string is converted twice (app→UTF-8, UTF-8→app) | Minimal – UTF-8 to UTF-16 or direct binary copy | | Parameter binding | Slower with mixed data (ANSI→UTF-8 conversion on each bind) | Faster – native wide char | | Sorting/Comparison | Done on server (UTF-8) – no client impact | Same | | LOB handling | Same as Unicode (bytea/text streaming) | Same |

1. Introduction: What is "PostgreSQL ANSI ODBC"? At its core, the phrase "PostgreSQL ANSI ODBC" refers to a specific driver configuration within the psqlODBC driver suite—the official ODBC driver for PostgreSQL. This driver allows applications to connect to a PostgreSQL database using the Open Database Connectivity (ODBC) API, while adhering strictly to the ANSI SQL standard for character data types. postgresql ansi odbc

PostgreSQL ANSI(x64) Or, if both drivers are installed: The driver expects UTF-8 on the wire