Class AdbNpgsqlTableInformationService

An optional service for a PostgreSQL® data source that manipulates table identifiers and provides information about table-like objects, such as which ones exists and what their type is (table, view, etc), and which columns are present. This assists with writing provider-independent database code, and is available as TableInformation. Also see HasTableInformationService, AdbNpgsqlTableCommandService, AdbNpgsqlDataSourceInformationService, AdbConnection and AdbProvider.

Derive from this class (or from a base or descendant class) to customize the information for either the same .NET provider, or for a different but similar .NET provider.

Inheritance
Object
AdbGenericTableInformationService
AdbNpgsqlTableInformationService
Implements
Inherited Members
Namespace: actionETL.Adb.NpgsqlExternal
Assembly: actionETL.dll
Syntax
public class AdbNpgsqlTableInformationService : AdbGenericTableInformationService, IAdbTableInformationService

Methods

Get()

Gets a function that returns a new instance of AdbNpgsqlTableInformationService on each invocation, which is used when instantiating a new AdbProvider for accessing a PostgreSQL® data source.

Declaration
public static Func<IAdbConnection, IAdbTableInformationService> Get()
Returns
Type Description
Func<IAdbConnection, IAdbTableInformationService>

GetTableColumnsAsync(IAdbTableIdentifier)

Gets information (name, data type etc.) about all columns in a table-like database object.

With a PostgreSQL® data source the following are supported by this method, and by workers using this method: tables (user, system, temporary, and partitioned) and views (user, system, and materialized).

Note that this method does not log errors. Instead the caller should normally log any returned failure status.

Declaration
public override async Task<OutcomeStatusResult<IList<AdbColumnSchema>>> GetTableColumnsAsync(IAdbTableIdentifier tableIdentifier)
Parameters
Type Name Description
IAdbTableIdentifier tableIdentifier

The identifier for a table-like object to check. It must specify table name, but schema and/or catalog names can be null, in which case the current schema and catalog for the connection is used. Providers where 'database' and 'schema' means the same thing, i.e. MySqlClient, put the database/schema in the schema property.

Returns
Type Description
Task<OutcomeStatusResult<IList<AdbColumnSchema>>>

On success, Status will be Succeeded, and Result will be populated with the table columns.

On failure, Status will have a failure status, and Result will be null.

An incorrect parameter will throw immediately. Any other exceptions or failures will be caught and contained in the returned OutcomeStatus, which should then be logged by the caller. If a .NET provider doesn't support retrieving this information, an Error status with a NotSupportedException is returned.

See the provider documentation for specific Open() exceptions. Some providers may throw if the connection is associated with a transaction.

Overrides
Exceptions
Type Condition
ArgumentException

tableIdentifier.UnquotedTableName cannot be null or only whitespace.
ArgumentNullException

tableIdentifier

GetTableTypeAsync(IAdbTableIdentifier)

Check if a table-like object exists, and what type (table, view, etc.) it is.

With a PostgreSQL® data source the following are supported by this method, and by workers using this method: tables (user, system, temporary, and partitioned) and views (user, system, and materialized).

Note that this method does not log errors. Instead the caller should normally log any returned failure status.

Declaration
public override async Task<OutcomeStatusResult<AdbTableType>> GetTableTypeAsync(IAdbTableIdentifier tableIdentifier)
Parameters
Type Name Description
IAdbTableIdentifier tableIdentifier

The identifier for a table-like object to check. It must specify table name, but schema and/or catalog names can be null, in which case the current schema and catalog for the connection is used. Providers where 'database' and 'schema' means the same thing, i.e. MySqlClient, put the database/schema in the schema property. See Identifiers and Key Words for details.
Returns
Type Description
Task<OutcomeStatusResult<AdbTableType>>

On success, Status will be Succeeded, and Result will describe if the table exists, and if so, what type (table, view, etc.)

On failure, Status will have a failure status, and Result will be undefined.

An incorrect parameter will throw immediately. Any other exceptions or failures will be caught and contained in the returned OutcomeStatus, which should then be logged by the caller.

See the provider documentation for specific Open() exceptions. Some providers may throw if the connection is associated with a transaction.

Overrides
Exceptions
Type Condition
ArgumentException

tableIdentifier.UnquotedTableName cannot be null or only whitespace.
ArgumentNullException

tableIdentifier

Implements

See Also