ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
SQL support in local databases
The LIMIT clause places an upper bound on the number of rows returned in the result. A negative LIMIT indicates
no upper bound. The optional OFFSET following LIMIT specifies how many rows to skip at the beginning of the result
set. In a compound SELECT query, the LIMIT clause may only appear after the final SELECT statement, and the limit
is applied to the entire query. Note that if the OFFSET keyword is used in the LIMIT clause, then the limit is the first
integer and the offset is the second integer. If a comma is used instead of the OFFSET keyword, then the offset is the
first number and the limit is the second number. This seeming contradiction is intentional — it maximizes
compatibility with legacy SQL database systems.
A compound SELECT is formed from two or more simple SELECT statements connected by one of the operators
UNION, UNION ALL, INTERSECT, or EXCEPT. In a compound SELECT, all the constituent SELECT statements
must specify the same number of result columns. There can only be a single ORDER BY clause after the final SELECT
statement (and before the single LIMIT clause, if one is specified). The UNION and UNION ALL operators combine
the results of the preceding and following SELECT statements into a single table. The difference is that in UNION, all
result rows are distinct, but in UNION ALL, there may be duplicates. The INTERSECT operator takes the intersection
of the results of the preceding and following SELECT statements. EXCEPT takes the result of preceding SELECT after
removing the results of the following SELECT. When three or more SELECT statements are connected into a
compound, they group from first to last.
For a definition of permitted expressions, see Expressions.
Starting with AIR 2.5, the SQL CAST operator is supported when reading to convert BLOB data to ActionScript
ByteArray objects. For example, the following code reads raw data that is not stored in the AMF format and stores it
in a ByteArray object:
stmt.text = "SELECT CAST(data AS ByteArray) AS data FROM pictures;";
stmt.execute();
var result:SQLResult = stmt.getResult();
var bytes:ByteArray = result.data[0].data;
INSERT
The INSERT statement comes in two basic forms and is used to populate tables with data.
sql-statement ::= INSERT [OR conflict-algorithm] INTO [database-name.] table-name [(columnlist)]
VALUES (value-list) |
INSERT [OR conflict-algorithm] INTO [database-name.] table-name [(columnlist)]
select-statement
REPLACE INTO [database-name.] table-name [(column-list)] VALUES (value-list) |
REPLACE INTO [database-name.] table-name [(column-list)] select-statement
The first form (with the VALUES keyword) creates a single new row in an existing table. If no column-list is specified
then the number of values must be the same as the number of columns in the table. If a column-list is specified, then
the number of values must match the number of specified columns. Columns of the table that do not appear in the
column list are filled with the default value defined when the table is created, or with NULL if no default value is
defined.
The second form of the INSERT statement takes its data from a SELECT statement. The number of columns in the
result of the SELECT must exactly match the number of columns in the table if column-list is not specified, or it must
match the number of columns named in the column-list. A new entry is made in the table for every row of the SELECT
result. The SELECT may be simple or compound. For a definition of allowable SELECT statements, see SELECT.
The optional conflict-algorithm allows the specification of an alternative constraint conflict resolution algorithm to
use during this one command. For an explanation and definition of conflict algorithms, see “Special statements and
clauses” on page 1103.
Last updated 6/6/2012
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