Query APIs
This page describes how to use query APIs to interact with the database.
Query APIs are a set of APIs created for users to programmatically interact with the database. The following functions are currently supported:
.com_kx_edi.getMeta
This function returns the metadata of the databases.
.com_kx_edi.getMeta[]
The getMeta API returns meta information on APIs defined in the DAPs and aggregation functions in the Aggs for all DAPs and Aggs in the system. Additionally, it returns information on the assemblies, schemas, metadata, and UDAs including their parameters and return values.
Assembly names
If you are using the assembly names from the getMeta[] function for .com_kx_edi.qsql, ensure the "-qe" is removed before invoking .com_kx_edi.qsql.
Returns:
| Type | Description |
|---|---|
| any[] | Metadata of the databases |
Example:
.com_kx_edi.getMeta[]
// List all UDAs
.com_kx_edi.getMeta[][1;`api]
// List all assemblies
.com_kx_edi.getMeta[][1;`assembly]
// List all tables
.com_kx_edi.getMeta[][1;`schema]
For more details, refer to the getMeta documentation.
.com_kx_edi.sql
This function runs an SQL query.
.com_kx_edi.sql[query]
The SQL API allows queries to be distributed/aggregated across multiple DAPs.
Required Parameters:
| Name | Description | Default |
|---|---|---|
| Query | A string that expresses the query you wish to run | Required |
Returns:
| Type | Description |
|---|---|
| any | Result of sql query |
Example:
.com_kx_edi.sql["SELECT * FROM table1 LIMIT 10"]
Refer to the SQL documentation for more details.
.com_kx_edi.qsql
This is a QSQL query builder that assembles QSQL queries based on a q expression.
.com_kx_edi.qsql[args]
This API is intended to run on a data access process and execute the command sent in from the client.
The args dictionary should be structured as follows:
args.assembly {string} The assembly name
args.target {string} The tier ("rdb", "idb", or "hdb")
args.query {string} A q expression
Required Parameters:
| Name | Description | Default |
|---|---|---|
| args | A dictionary that contains the assembly, target, and q query | Required |
Returns:
| Type | Description |
|---|---|
| any | Result of q expression |
Example:
// List all assemblies
q).com_kx_edi.getMeta[][1;`assembly]
assembly kxname tbls
------------------------------------------------------
example-pkg-qe trades-db trades
// The "-qe" must be omitted from the assembly name
q).com_kx_edi.qsql[`assembly`target`query!("example-pkg";"rdb";"select max bid from trades")]
For more information, refer to the QSQL documentation.
.com_kx_edi.queryBuilder
The queryBuilder function uses the GetData API to construct queries.
.com_kx_edi.queryBuilder[args]
The queryBuilder uses arguments found in GetData API.
The Query Builder is a generic data retrieval API that can be executed against an arbitrary database table. It is intended to run on a Data Access Process and retrieve records from a configured database table using a specified dictionary of parameters, as specified below.
Required Parameters:
| Name | Description | Default |
|---|---|---|
| args | The list of arguments can be found in the getData parameters | Required |
Returns:
| Type | Description |
|---|---|
| table | Result of table query |
Example:
.com_kx_edi.queryBuilder[`table`startTS`endTS!("table1";2024.01.01D; 2024.01.02D)]
.com_kx_edi.uda
Use this function to query a UDA.
.com_kx_edi.uda[args;name]
Refer to these example UDAs for more details
The UDA API allows you to directly query a UDA against databases within a package.
Required Parameters:
| Name | Description | Default |
|---|---|---|
| args | A dictionary of UDA defined parameters. | Required |
| name | The name of the UDA including namespace in the form of namespace/udaName, such as example/daAPI |
Required |
Returns:
| Type | Description |
|---|---|
| any | Result of UDA |
Example:
args:`table`column`multiplier`startTS`endTS!(`table1;`column1;10;2024.11.06D;2024.11.21D);
.com_kx_edi.uda[args;"example/daAPI"]