SAP::DBTech::sapdb (Perl)

• class SapDB_Session
  • sql: Executes an SQL statement.
  • sqlX: Executes an SQL statement with arguments.
  • prepare: Prepares an SQL statement and creates resulting an SapDB_Prepared object.
  • release: Closes the connection.
  • commit: Commits the current transaction.
  • rollback: Aborts the current transaction.
• class SapDB_ResultSet
  • next: Gets the next row.
  • previous: Gets the previous row.
  • relative: Moves the cursor relatively to the current row.
  • absolute: Gets the row no. i.
  • first: Gets the first row.
  • last: Gets the last row.
  • current: Returns the current row.
  • cursorName: Returns the name of the result set.
  • columnCount: Returns the number of columns.
  • columnInfo: Returns information about a column.
  • getDescription: Returns information about the output columns.
• class SapDB_LongReader
  • read: Returns the subsequent count characters.
• class SapDB_Prepared
  • execute: Executes a statement with arguments.
  • getDescription: Returns information about the parameters.
• connect: Creates a SapDB_Session with a database.
  
  
• _buildInfo: Returns a string containing the version and build number.
  
  

• Input
• Output

• How to test SQL features
• How to insert LONG columns in a database and SELECT them

• CommunicationError
• SQLError

Module Contents

class SapDB_Session

Allows the execution of SQL statements.
When the last reference to the session is dropped the database connection is released with an implicit transaction rollback.

sql

$sqlResult = $session->sql ($cmd)

Executes an SQL statement.
Returns data values on SELECT INTO, a SapDB_ResultSet on SELECT and otherwise an empty list.

sqlX

$sqlResult = $session->sqlX ($cmd [, $params])

Executes an SQL statement with arguments.
Returns data values on SELECT INTO, an SapDB_ResultSet on SELECT and otherwise the number of the affected records. The arguments must not be given as an array but as a reference to an array: [$a, $b, ...].

prepare

$session->prepare ($cmd)

Parses an SQL statement and creates an SapDB_Prepared object.

release

$session->release ( [$withCommit])

Closes the connection. The default is to end the session without COMMIT.

commit

$session->commit ()

Commits the current transaction.

rollback

$session->rollback ()

Aborts the current transaction.

class SapDB_ResultSet

Allows navigation and the retrieval of a result set.
Objects are created by all SQL statements that create a result set
(SapDB_Session::sql, SapDB_Prepared::execute).

next

$result = $resultSet->next ()

Gets the next row.
Output values are returned as a list. The end of the result set is indicated by an undefined value.

previous

$result = $resultSet->previous ()

Gets the previous row.
Output values are returned as a list. The end of the result set is indicated by an undefined value.

relative

$result = $resultSet->relative ($count)

Moves the cursor relatively to the current row.
A negative value of count will move the cursor backwards in the result set. Output values are returned as a list. The end of the result set is indicated by an undefined value.

absolute

$result = $resultSet->absolute ($i)

Gets the row no. i.
Output values are returned as a list. The first row has the index 1. The end of the result set is indicated by an undefined value.

first

$result = $resultSet->first ()

Gets the first row.
Output values are returned as a list. The end of the result set is indicated by an undefined value.

last

$result = $resultSet->last ()

Gets the last row.
Output values are returned as a list. The end of the result set is indicated by an undefined value.

current

$result = $resultSet->current ()

Returns the current row.
Output values are returned as a list.

cursorName

$result = $resultSet->cursorName ()

Returns the name of the result set.

columnCount

$result = $resultSet->columnCount ()

Returns the number of columns.

columnInfo

$result = $resultSet->columnInfo ($i)

Returns information about a column specifying four values:

• column name
• column type
• length of the column
• number of fractional digits

The first column has the index 0.

getDescription

$result = $resultSet->getDescription ();

Returns information about the output columns.
A reference to an array is returned. Each array element consists of a reference to a column description. A column description is an array with the following elements:

• column name
• column type as a string
• column type as an ANSI/ODBC type integer
• length of the column
• number of fractional digits
• specification whether the column may contain NULL
• specification whether the column is IN, OUT or IN/OUT (always OUT)

Example:

my $descriptions = $resultSet->getDescription ();
foreach my $description (@{$descriptions}) {
    my ($name, $typeName, $typeCode,
        $colLength, $colPrecision, $isNullable, $inout)
        = @{$description};
}

class SapDB_LongReader

Allows to retrieve LONGs.

read

$result = $reader->read ($count)

Returns the subsequent count characters.
Returns an empty string when the end of the LONG is reached.

class SapDB_Prepared

Allows the execution of SQL statements with parameters.
Objects are created with SapDB_Session::prepare.

execute

$result = $prepared->execute ( [$sqlParms])

Executes statements with arguments.
Output values are returned as a list. If the statement creates a result set, then a SapDB_ResultSet is returned. The arguments must not be specified as an array but as a reference to an array [$a, $b, ...].

getDescription

$result = $prepared->getDescription ();

Returns information about the parameters. A reference to an array is returned. Each array element consists of a reference to a parameter description. A parameter desvription is an array with the following elements:

• parameter name (currently the empty string)
• parameter type as a string
• parameter type as an ANSI/ODBC type integer
• length of the parameter
• number of fractional digits
• specification whether the parameter may contain NULL
• specification whether the parameter is IN, OUT or IN/OUT

Example:

my $descriptions = $prepared->getDescription ();
foreach my $description (@{$descriptions}) {
    my ($name, $typeName, $typeCode,
    $colLength, $colPrecision, $isNullable, $inout)
        = @{$description};
}

connect

$session = sapdb::connect ($user, $pwd, $dbname [, $host [, $config]])

Establishes the connection to the database.
The username is case sensitive. config is a string of the following format:
keyword=value[&keyword=value]...
Allowed keywords are:

• sqlmode (internal, oracle)
• isolation (isolation level as an integer)
• timeout (command timeout in seconds)

_buildInfo

$result = sapdb::_buildInfo ()

Returns a string containing the version and build number.

Long Values

Input

Input values for LONGs can be either a string or a callable object with the following properties:

• The object is called with an integer argument, number of bytes requested
• The object must return a string
• The end of the stream is indicated by an empty string

Output

Output values of LONGs are of the type SapDB-LongReader and can be read using the method read.

Installation

1. Change to the directory <dependent_path>/misc
2. Execute the Perl script instperl.pl sapdb

Examples

How to test SQL features: egSQL.pl

How to test inserts of LONGs and SELECT them: longtest.pl

Exceptions

• CommunicationError: The communication link to the server failed.
• SQLError: The execution of the SQL statement resulted in an error.

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