INSERT Statement

Syntax 

INSERT INTO table_identifier '('column_identifier[,...]')' 
  SELECT target_list_1 FROM stream_expression
  [RETURNING target_list_2]
  [ERROR INTO stream_identifier];

Substitutable Fields

table_identifier

The unique identifier (name) of the table into which to insert the new entries.

column_identifier

The unique identifier (name) of a column into which a new value will be inserted.

target_list

One or more entries, separated by commas, of the format target_list_entry. Entries in target_list_1 are inserted into the table; entries in target_list_2 are emitted as a tuple onto the output stream. 

INSERT ... RETURNING target_list_2 INTO stream_identifier;
target_list_entry

A value, of the format scalar_expression [AS output_field_identifier], to be included in the result set returned by the statement. .

scalar_expression

An expression that generates a value for a tuple field. Values can be obtained from a tuple field, from a simple function, or from the table. Optionally, the name for a value can be modified through an AS clause.

stream_expression

A stream expression, for example a SELECT clause, which provides the values to be inserted into the table.

output_field_identifier

A unique identifier (name) for the tuple field that contains a value returned by the insert operation

ERROR INTO Clause

You can append an ERROR INTO clause just before the closing semicolon. The StreamSQL ERROR INTO clause is analogous to the Enable Error Output Port check box for operators and adapters in EventFlow applications.

Use ERROR INTO with the name of a stream, which must already exist. This sets up an Error Port for this operator, which is much like a local catch mechanism for errors from this operator.

See Using Error Ports and Error Streams for a discussion of StreamBase error handling mechanisms.

Discussion

The INSERT statement inserts a new row into an existing table.

With the INSERT statement, the INTO clause lists the table fields that will be populated with data. The stream_expression is a SELECT clause against a stream whose tuples contain the data that will be entered into the table. Its target list identifies the tuple fields that will provide the content for each table field.

If all of the tuple fields will be entered into the table, and the fields are in an order that corresponds to the order of table fields, use * as the target list. Otherwise the target list must explicitly extract each tuple field, as illustrated below. 

SELECT * FROM stream_identifier
SELECT tuple_field_identifier[, ...] FROM stream_identifier

In the RETURNING clause, scalar_expression can specify a value from the stream and/or from the table. For example: 

INSERT ...
  RETURNING tuple_field_identifier [AS ...][, ...], column_identifier [AS ...][, ...]

The result set generated by the RETURNING clause must be captured into a stream. You can use the CREATE STREAM statement to define a stream and the INTO keyword to populate the stream with the content generated by the RETURNING clause. Alternatively, in a single statement you can use the => (arrow) operator with a CREATE STREAM statement, as illustrated below. 

CREATE STREAM stream_identifier;
INSERT ... RETURNING ... INTO stream_identifier;

Or 

INSERT ... RETURNING ... => CREATE STREAM stream_identifier

Related Topics

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