Java Reference
In-Depth Information
pstmt.executeUpdate();
}
}
Thisexamplefirstcreatesa
String
objectthatspecifiesanSQL
INSERT
statement.
Each“
?
”characterservesasaplaceholderforavaluethat'sspecifiedbeforethestate-
ment is executed.
After the
PreparedStatement
implementation instance has been obtained, this
interface's
void setInt(int parameterIndex, int x)
and
void
setString(int parameterIndex, String x)
methods are called on
this instance to provide these values (the first argument passed to each method is
a 1-based integer column index into the table associated with the statement—1 cor-
responds to the leftmost column), and then
PreparedStatement
's
int ex-
ecuteUpdate()
method is called to execute this SQL statement. The end result: a
pair of rows containing
John Doe
,
Sally Smith
, and their respective identifiers
are added to the
EMPLOYEES
table.
CallableStatement
CallableStatement
isthemostspecializedofthestatementinterfaces;itextends
PreparedStatement
. You use this interface to execute SQL stored procedures,
wherea
stored procedure
isalistofSQLstatementsthatperformaspecifictask(e.g.,
fire an employee). Java DB differs from other RDBMSes in that a stored procedure's
body is implemented as a
public static
Java method. Furthermore, the class in
which this method is declared must be
public
.
You create a stored procedure by executing an SQL statement that typically begins
with
CREATE PROCEDURE
andthencontinueswithRDBMS-specificsyntax.Forex-
ample,theJavaDBsyntaxforcreatingastoredprocedure,asspecifiedonthewebpage
cedurestatement.html
,
is as follows:
CREATE PROCEDURE
procedure-name
([
procedure-parameter
[,
procedure-parameter
] ]*)
[
procedure-element
]*
procedure-name
is expressed as
[
schemaName
.]
SQL92Identifier
procedure-parameter
is expressed as
[{ IN | OUT | INOUT }] [
parameter-Name
]
DataType