DuckDB function reference¶

The laterite_ags4 extension registers these table functions. See the DuckDB surface page for worked examples.

INSTALL laterite_ags4 FROM community;
LOAD laterite_ags4;

Validation & certification live elsewhere¶

This extension is a read-only reader — there is no validate_ags / certify_ags in SQL. Run the numbered rules and mint an .ags.idx certificate with the lat CLI (lat validate / lat certify) or the laterite Python/Node library. read_ags then consumes an externally-minted .ags.idx beside the file to range-read a single group's bytes instead of parsing the whole file.

read_ags accepts encoding := 'windows-1252' to decode a legacy file.

Read¶

Function	Returns
`read_ags(path, group)`	one group, columns cast to their AGS4 types.
`read_ags_text(content, group)`	the same, from an AGS4 string instead of a path.

SELECT loca_id, loca_gl FROM read_ags('delivery.ags', 'LOCA') WHERE loca_gl < 0;

Every group is a table function, so joins are plain SQL:

SELECT s.samp_id, g.geol_leg
FROM read_ags('delivery.ags', 'SAMP') s
JOIN read_ags('delivery.ags', 'GEOL') g USING (loca_id);

Inspect the file¶

Function	Returns
`ags_groups(path)`	the groups present in the file, with per-group row and heading counts.
`ags_headings(path)`	every group's headings — unit, `ags_type`, `sql_type`, `is_key` — with a `group` column to filter on.

Inspect the dictionary¶

The AGS4 dictionary ships inside the extension — no download.

Function	Returns
`ags_dictionary()`	every group/heading with its unit and data type.
`ags_relationships()`	the group parent/child (KEY) graph.
`ags_rules()`	the AGS4 numbered-rule catalogue (`rule`, `title`, `severity`, `fixable`) — the extension lists the rules; the CLI/library run them.

SELECT heading, unit, ags_type, sql_type FROM ags_dictionary() WHERE "group" = 'LOCA';

Materialise a store¶

load_ags emits the CREATE TABLE DDL to persist every group as an indexed, repeat-/remote-queryable store — turning a one-shot read into a durable database.

Function	Returns
`load_ags(path)`	`(seq, stmt)` — ordered `CREATE TABLE` DDL, one statement per row.

SELECT stmt FROM load_ags('delivery.ags') ORDER BY seq;

Read-only query surface

DuckDB is a read door — it reads and inspects, but doesn't validate, certify, fix, diff, or emit AGS4 (those are the library and CLI surfaces). See the capability matrix.