6.2. INSERT
Used forInserting rows of data into a table
Available inDSQL, ESQL, PSQL
Syntax
|
INSERT INTO target
| {DEFAULT VALUES | [(<column_list>)] <value_source>}
| [RETURNING <returning_list> [INTO <variables>]]
|
|<column_list> ::= colname [, colname ...]
|
|<value_source> ::= VALUES (<value_list>) | <select_stmt>
|
|<value_list> ::= <value> [, <value> ...]
|
|<returning_list> ::=
| <ret_value> [[AS] ret_alias] [, <ret_value> [[AS] ret_alias] ...]
|
|<ret_value> ::= { colname | target.colname | <value> }
|
|<variables> ::= [:]varname [, [:]varname ...]
INSERT
Statement ParametersArgument | Description |
---|---|
target | The name of the table or view to which a new row, or batch of rows, should be added |
colname | Column in the table or view |
value | An expression whose value is used for inserting into the table or for returning |
ret_value | The expression to be returned in the |
varname | Name of a PSQL local variable |
The INSERT
statement is used to add rows to a table or to one or more tables underlying a view:
If the column values are supplied in a
VALUES
clause, exactly one row is insertedThe values may be provided instead by a
SELECT
expression, in which case zero to many rows may be insertedWith the
DEFAULT VALUES
clause, no values are provided at all and exactly one row is inserted.
Columns returned to the
NEW.column_name
context variables in triggers should not have a colon (
) prefixed to their names:
No column may appear more than once in the column list.
BEFORE INSERT
TriggersRegardless of the method used for inserting rows, be mindful of any columns in the target table or view that are populated by BEFORE INSERT
triggers, such as primary keys and case-insensitive search columns.
Those columns should be excluded from both the column_list and the VALUES
list if, as they should, the triggers test the NEW.column_name
for NULL
.
6.2.1. INSERT … VALUES
The VALUES
list must provide a value for every column in the column list, in the same order and of the correct type.
The column list need not specify every column in the target but, if the column list is absent, the engine requires a value for every column in the table or view (computed columns excluded).
Introducer syntax provides a way to identify the character set of a value that is a string constant (literal). Introducer syntax works only with literal strings: it cannot be applied to string variables, parameters, column references or values that are expressions.
Examples
|
INSERT INTO cars (make, model, year)
|VALUES ('Ford', 'T', 1908);
|
|INSERT INTO cars
|VALUES ('Ford', 'T', 1908, 'USA', 850);
|
|-- notice the '_' prefix (introducer syntax)
|INSERT INTO People
|VALUES (_ISO8859_1 'Hans-Jörg Schäfer');
6.2.2. INSERT … SELECT
For this method of inserting, the output columns of the SELECT
statement must provide a value for every target column in the column list, in the same order and of the correct type.
Literal values, context variables or expressions of compatible type can be substituted for any column in the source row.
In this case, a source column list and a corresponding VALUES
list are required.
If the column list is absent — as it is when SELECT *
is used for the source expression — the column_list must contain the names of every column in the target table or view (computed columns excluded).
Examples
|
INSERT INTO cars (make, model, year)
| SELECT make, model, year
| FROM new_cars;
|
|INSERT INTO cars
| SELECT * FROM new_cars;
|
|INSERT INTO Members (number, name)
| SELECT number, name FROM NewMembers
| WHERE Accepted = 1
|UNION ALL
| SELECT number, name FROM SuspendedMembers
| WHERE Vindicated = 1
|
|INSERT INTO numbers(num)
| WITH RECURSIVE r(n) as (
| SELECT 1 FROM rdb$database
| UNION ALL
| SELECT n+1 FROM r WHERE n < 100
| )
|SELECT n FROM r
Of course, the column names in the source table need not be the same as those in the target table.
Any type of SELECT
statement is permitted, as long as its output columns exactly match the insert columns in number, order and type.
Types need not be exactly the same, but they must be assignment-compatible.
When using and INSERT … SELECT
with a RETURNING
clause, the SELECT
has to produce at most one row, as RETURNING
currently only works for statements affecting at most one row.
This behaviour may change in future Firebird versions.
6.2.3. INSERT … DEFAULT VALUES
The DEFAULT VALUES
clause allows insertion of a record without providing any values at all, either directly or from a SELECT
statement.
This is only possible if every NOT NULL
or CHECK
ed column in the table either has a valid default declared or gets such a value from a BEFORE INSERT
trigger.
Furthermore, triggers providing required field values must not depend on the presence of input values.
Example
|
INSERT INTO journal
| DEFAULT VALUES
|RETURNING entry_id;
6.2.4. The RETURNING
clause
An INSERT
statement adding at most one row may optionally include a RETURNING
clause in order to return values from the inserted row.
The clause, if present, need not contain all of the insert columns and may also contain other columns or expressions.
The returned values reflect any changes that may have been made in BEFORE INSERT
triggers.
The optional INTO
sub-clause is only valid in PSQL.
INSERT
sIn DSQL, a statement with RETURNING
always returns only one row.
If the RETURNING
clause is specified and more than one row is inserted by the INSERT
statement, the statement fails and an error message is returned.
This behaviour may change in future Firebird versions.
Examples
|
INSERT INTO Scholars (
| firstname,
| lastname,
| address,
| phone,
| email)
|VALUES (
| 'Henry',
| 'Higgins',
| '27A Wimpole Street',
| '3231212',
| NULL)
|RETURNING lastname, fullname, id;
|
|INSERT INTO Dumbbells (firstname, lastname, iq)
| SELECT fname, lname, iq
|FROM Friends
| ORDER BY iq ROWS 1
| RETURNING id, firstname, iq
|INTO :id, :fname, :iq;
RETURNING
is supported forVALUES
andDEFAULT VALUES
inserts, and singletonSELECT
inserts.In DSQL, a statement with a
RETURNING
clause always returns exactly one row. If no record was actually inserted, the fields in this row are allNULL
. This behaviour may change in a later version of Firebird. In PSQL, if no row was inserted, nothing is returned, and the target variables keep their existing values.
6.2.5. Inserting into BLOB
columns
Inserting into BLOB
columns is only possible under the following circumstances:
The client application has made special provisions for such inserts, using the Firebird API. In this case, the modus operandi is application-specific and outside the scope of this manual.
The value inserted is a string literal of no more than 65,533 bytes (64KB - 3).
ⓘNoteA limit, in characters, is calculated at run-time for strings that are in multi-byte character sets, to avoid overrunning the bytes limit. For example, for a UTF8 string (max. 4 bytes/character), the run-time limit is likely to be about (floor(65533/4)) = 16383 characters.
You are using the
form and one or more columns in the result set areINSERT … SELECT
BLOB
s.