API Reference¶

Complete reference for all YAML extension functions, parameters, and capabilities.

Overview¶

The YAML extension provides:

Section	Description
Table Functions	Functions that return tables
Scalar Functions	Functions that return single values
Parameters	All configurable parameters

Function	Description
`read_yaml(path, ...)`	Read YAML files into rows
`read_yaml_objects(path, ...)`	Read files preserving structure
`read_yaml_frontmatter(path, ...)`	Extract YAML frontmatter
`parse_yaml(string, ...)`	Parse YAML string into rows
`yaml_each(yaml)`	Iterate object key-value pairs
`yaml_array_elements(yaml)`	Unnest array elements

Function	Returns	Description
`yaml_extract(yaml, path)`	YAML	Extract value at path
`yaml_extract_string(yaml, path)`	VARCHAR	Extract as string
`yaml_exists(yaml, path)`	BOOLEAN	Check path existence
`yaml_type(yaml [, path])`	VARCHAR	Get value type
`yaml_keys(yaml [, path])`	VARCHAR[]	Get object keys
`yaml_array_length(yaml [, path])`	BIGINT	Get array length
`yaml_to_json(yaml)`	JSON	Convert to JSON
`value_to_yaml(any)`	YAML	Convert to YAML
`format_yaml(yaml, style)`	VARCHAR	Format with style
`yaml_valid(string)`	BOOLEAN	Validate YAML
`yaml_build_object(...)`	YAML	Build from pairs
`from_yaml(string, struct)`	Struct	Parse to struct

Function	Description
`yaml_set_default_style(style)`	Set output style
`yaml_get_default_style()`	Get current style

COPY table TO 'file.yaml' (FORMAT yaml [, STYLE style] [, LAYOUT layout])

The YAML type is a specialized VARCHAR:

-- Create YAML values
SELECT 'name: John'::YAML;
SELECT value_to_yaml({'key': 'value'});

-- Use in columns
CREATE TABLE t (data YAML);

Used by extraction functions:

Most functions return NULL on error. Use ignore_errors parameter in read functions to continue on errors.