Class AdbGenericTableInformationService

An optional service 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, AdbTableCommand, AdbDataSourceInformation, AdbConnection and AdbProvider.

Derive from this class (or from one of its descendant classes) to customize the information for either a new .NET provider, or to tweak an existing one.

This class is immutable. This avoids threading issues, since an instance is often accessed by multiple threads. Any user custom provider services should also be immutable for the same reason.

Inheritance
Object
AdbGenericTableInformationService
AdbMySqlClientTableInformationService
AdbMySqlConnectorTableInformationService
AdbNpgsqlTableInformationService
AdbOdbcTableInformationService
AdbSqlClientTableInformationService
AdbSQLiteTableInformationService
Implements
Namespace: actionETL.Adb
Assembly: actionETL.dll
Syntax
public abstract class AdbGenericTableInformationService : IAdbTableInformationService
Remarks

Notes to implementers:

The AdbTableInformation class ensures the table name is not null or whitespace, so implementations of this interface do not need to check this. Note however that the schema and catalog parts can be null or whitespace.

Constructors

AdbGenericTableInformationService(IAdbConnection)

Initializes a new instance of the AdbGenericTableInformationService class, an optional service which manipulates table identifiers and provides information about tables, such as what tables and columns are present.

Declaration
protected AdbGenericTableInformationService(IAdbConnection adbConnection)
Parameters
Type Name Description
IAdbConnection adbConnection

A database connection.

Properties

Connection

Gets the database connection to run commands on.

Declaration
protected IAdbConnection Connection { get; }
Property Value
Type Description
IAdbConnection

Methods

ComposeTableIdentifierParts(String, String, String)

Composes the table identifier parts into a composite table identifier string.

Each specified part must follow the quoting requirements of the provider, e.g. use quoting due to potential spaces in the part name (i.e. parts won't be automatically quoted).

Declaration
public virtual string ComposeTableIdentifierParts(string quotedTableName, string quotedSchemaName, string quotedCatalogName)
Parameters
Type Name Description
String quotedTableName

Name of the table, with quoting if required. Cannot be null or only whitespace.
String quotedSchemaName

Name of the schema, with quoting if required, or null to not set it.
String quotedCatalogName

Name of the catalog, with quoting if required, or null to not set it. Catalog is normally the database if the provider uses it (e.g. SqlClient); otherwise null if unused (e.g. MySqlClient provider).
Returns
Type Description
String

The combined table identifier string.
Exceptions
Type Condition
ArgumentException

quotedTableName cannot be null or only whitespace.

CreateTableIdentifier(String)

Creates an identifier for a table-like database object from a composite name, i.e. it splits a potentially delimited table name into its constituent parts, i.e. database or catalog name, schema or owner name, and table name. Depending on the provider, the identifier can be either system or user regular tables, temporary tables, views, table-valued functions, etc.

Note that some providers do not support all identifier parts; unsupported parts will be set to null, but unused parts will be set to an empty string. While the SqlClient provider puts the database and schema in the CatalogName and SchemaName properties respectively, the MySqlClient provider puts the database in the SchemaName property.

Declaration
public virtual IAdbTableIdentifier CreateTableIdentifier(string compositeTableName)
Parameters
Type Name Description
String compositeTableName

Name of the table, potentially including database or catalog name, and schema or owner name.

The string must be formatted according to the requirements of the data source, i.e. use the appropriate quoting characters and delimiters, in the appropriate order.

Returns
Type Description
IAdbTableIdentifier

A table identifier.
Exceptions
Type Condition
ArgumentException

compositeTableName cannot be null or only whitespace.

GetTableColumnsAsync(IAdbTableIdentifier)

Gets information (name, data type etc.) about all columns in a table-like database object. Depending on the provider, this can include both system and user regular tables, temporary tables, views, table-valued functions, etc.

Note that it does not include objects that do not themselves have columns, e.g. stored procedures.

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

Declaration
public abstract 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.

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 it is. Depending on provider, this can e.g. be a regular table, temporary table, view, table-valued function etc. It does not include stored procedures etc. that do not themselves have columns.

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

Declaration
public abstract 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.

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.

Exceptions
Type Condition
ArgumentException

tableIdentifier.UnquotedTableName cannot be null or only whitespace.
ArgumentNullException

tableIdentifier

Implements

See Also