Want to upsert data from CSV file to existing PostgreSQL table via command line on Windows?
Using pg-cmd, a Command-Line client for PostgreSQL, you can upsert(merge) CSV/TSV/TXT data to PostgreSQL table easily and fast.
Support Windows, Linux, and MacOS.
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No need to install PostgreSQL client library.
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Upsert/Merge CSV/TSV/TXT data into PostgreSQL table via command line on Windows
1. In interactive mode:
pg-cmd> load loadtype=upsert
> updatekey=id
> table=media_messages
> datafile=f:\media_messages.csv
> delimiter=,
> quote="
> header=y;
2. In batch mode:
pg-cmd dsn="pan:withdata@192.168.0.102/test" task=load loadtype=upsert updatekey=id table=media_messages datafile=f:\media_messages.csv delimiter=, quote=" header=y quit=y
“loadtype=upsert” will update row in table if “updatekey” id exists, or insert new row.
See parameters detail.
More about pg-cmd – Command-Line client for PostgreSQL
Download pg-cmd Windows version
CSV → PostgreSQL reference
Type mapping
| Value kind | in CSV | in PostgreSQL |
|---|---|---|
| Int | 1234 | integer |
| Bigint | 9007199254740993 | bigint |
| Decimal | 1234.56 | numeric(p,s) |
| Float | 1.234e+10 | double precision |
| Text | quoted only when it contains a comma or a quote | varchar(n) |
| Long text | must be quoted; line breaks inside force multi-line records | text |
| Date | 2026-09-18 | date |
| Datetime | 2026-09-18 14:30:00 | timestamp |
| Binary | not representable - base64 or hex string | bytea |
| Boolean | TRUE / FALSE, or 1 / 0 depending on the writer | boolean |
| JSON | the whole JSON value quoted, with internal quotes doubled | jsonb |
Dialect differences
CSV is a file format and PostgreSQL is a database server, so the target has to be told the types the file never carried – the rows below are where the two sides diverge.
| Property | in CSV | in PostgreSQL |
|---|---|---|
| port | — | 5432 |
| identifiers | Double quotes; a literal quote is doubled ("" ) | "double quotes" |
| row limit | — | LIMIT n |
| dates | Conventional text: 2026-09-18 or 2026-09-18 14:30:00 | timestamp, timestamptz, date, time |
| long text | — | TEXT |
| binary | Not supported | BYTEA |
| separator | Comma "," | — |
| encoding | No declaration - UTF-8 works only with a BOM | — |
| typing | None - every field is text | — |
| shape | Flat table, optional header row | Tables of rows and columns |
| ceiling | No formal limit; row count bounded by memory | — |
Command line
| Side | Command |
|---|---|
| PostgreSQL | pg_dump or COPY ... TO |
| PostgreSQL (load) | COPY ... FROM |
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