Schema/Metadata API Reference: Common syntax definitions

TableName

String | QualifiedTable

QualifiedTable

{
    "name": String,
    "schema": String
}

FunctionName

String | QualifiedFunction

QualifiedFunction

{
    "name": String,
    "schema": String
}

RoleName

String

ComputedFieldName

String

PGColumnType

String
  1. Numeric types

    Type Alias Description
    serial   autoincrementing integer
    bigserial   autoincrementing bigint
    integer   4 bytes, typical choice for integer
    smallint   2 bytes
    bigint   8 bytes
    real float4 6 decimal digits precision, inexact
    double precision float8 15 decimal digits precision, inexact
    numeric decimal arbitrary precision, exact
  2. Character types

    Type Alias Description
    varchar text typical choice for storing string types
  3. Date/Time types

    Type Alias Description
    timestamp with time zone timestamptz both date and time, with time zone. Allowed values should be of ISO8601 format. E.g. 2016-07-20T17:30:15Z, 2016-07-20T17:30:15+05:30, 2016-07-20T17:30:15.234890+05:30
    time with time zone timetz time of day only, with time zone. Allowed values should be of ISO8601 format. E.g. 17:30:15Z, 17:30:15+05:30, 17:30:15.234890+05:30
    date   date (no time of day). Allowed values are yyyy-mm-dd
  4. Boolean type

    Type Alias Description
    boolean   state of true or false
  5. JSON types

    Type Alias Description
    json   Stored as plain text
    jsonb   Stored in a binary format and can be indexed

PGColumn

String

RelationshipName

String

AndExp

{
    "$and" : [BoolExp],
}

OrExp

{
    "$or"  : [BoolExp],
}

NotExp

{
    "$not" : BoolExp
}

ExistsExp

{
    "$exists" : {
         "_table": TableName,
         "_where": BoolExp
    }
}

TrueExp

 {}

ColumnExp

{
    PGColumn : { Operator : Value }
}

Operator

Generic operators (all column types except json, jsonb) :

Operator PostgreSQL equivalent
"$eq" =
"$ne" <>
"$gt" >
"$lt" <
"$gte" >=
"$lte" <=
"$in" IN
"$nin" NOT IN

(For more details, refer to the Postgres docs for comparison operators and list based search operators.)

Text related operators :

Operator PostgreSQL equivalent
"$like" LIKE
"$nlike" NOT LIKE
"$ilike" ILIKE
"$nilike" NOT ILIKE
"$similar" SIMILAR TO
"$nsimilar" NOT SIMILAR TO

(For more details on text related operators, refer to the Postgres docs.)

Operators for comparing columns (all column types except json, jsonb):

Operator PostgreSQL equivalent
"$ceq" =
"$cne" <>
"$cgt" >
"$clt" <
"$cgte" >=
"$clte" <=

(For more details on comparison operators, refer to the Postgres docs.)

Checking for NULL values :

Operator PostgreSQL equivalent
_is_null (takes true/false as values) IS NULL

(For more details on the IS NULL expression, refer to the Postgres docs.)

JSONB operators :

Operator PostgreSQL equivalent
_contains @>
_contained_in <@
_has_key ?
_has_keys_any ?!
_has_keys_all ?&

(For more details on JSONB operators, refer to the Postgres docs.)

PostGIS related operators on GEOMETRY columns:

Operator PostGIS equivalent
_st_contains ST_Contains(column, input)
_st_crosses ST_Crosses(column, input)
_st_equals ST_Equals(column, input)
_st_intersects ST_Intersects(column, input)
_st_overlaps ST_Overlaps(column, input)
_st_touches ST_Touches(column, input)
_st_within ST_Within(column, input)
_st_d_within ST_DWithin(column, input)

(For more details on spatial relationship operators, refer to the PostGIS docs.)

Note

  • All operators take a JSON representation of geometry/geography values as input value.

  • The input value for _st_d_within operator is an object:

    {
      field-name : {_st_d_within: {distance: Float, from: Value} }
    }
    

Object

A JSONObject

{
   "k1" : v1,
   "k2" : v2,
   ..
}

Empty Object

An empty JSONObject

{}

ColumnPresetsExp

A JSONObject of a Postgres column name to value mapping, where the value can be static or derived from a session variable.

{
   "column1" : colVal1,
   "column2" : colVal2,
   ..
}

E.g. where id is derived from a session variable and city is a static value.

{
   "id" : "x-hasura-User-Id",
   "city" : "San Francisco"
}

Note

If the value of any key begins with “x-hasura-” (case-insensitive), the value of the column specified in the key will be derived from a session variable of the same name.

RemoteSchemaName

String

RemoteSchemaDef

{
   "url" : url-string,
   "url_from_env" : env-var-string,
   "headers": [
        { "name": header-name-string,
          "value": header-value-string,
          "value_from_env": env-var-string
        }
   ],
   "forward_client_headers": boolean,
   "timeout_seconds": integer
}

CollectionName

String

QueryName

String

CollectionQuery

{
    "name": String,
    "query": String
}

CustomColumnNames

A JSONObject of Postgres column name to GraphQL name mapping

{
   "column1" : String,
   "column2" : String,
   ..
}

ActionName

String

WebhookURL

A String value which supports templating environment variables enclosed in {{ and }}.

String

Template example: https://{{ACTION_API_DOMAIN}}/create-user

HeaderFromValue

Key required Schema Description
name true String Name of the header
value true String Value of the header

HeaderFromEnv

Key required Schema Description
name true String Name of the header
value_from_env true String Name of the environment variable which holds the value of the header

GraphQLType

A GraphQL Type Reference string.

String

Example: String! for non-nullable String type and [String] for array of String types

GraphQLName

A string literal that conform to GraphQL spec.

String