# cubrid_get_db_parameter

(PECL CUBRID >= 8.3.0)

cubrid_get_db_parameter — Returns the CUBRID database parameters

### 说明

cubrid_get_db_parameter ( resource `$conn_identifier` ) : array

This function returns the CUBRID database parameters or it returns FALSE on failure. It returns an associative array with the values for the following parameters:

- `PARAM_ISOLATION_LEVEL`
- `PARAM_LOCK_TIMEOUT`
- `PARAM_MAX_STRING_LENGTH`
- `PARAM_AUTO_COMMIT`

Database parameters
Parameter | Description
--- | ---
PARAM_ISOLATION_LEVEL | The transaction isolation level.
LOCK_TIMEOUT | CUBRID provides the lock timeout feature, which sets the waiting time (in seconds) for the lock until the transaction lock setting is allowed. The default value of the lock_timeout_in_secs parameter is -1, which means the application client will wait indefinitely until the transaction lock is allowed.
PARAM_AUTO_COMMIT | In CUBRID PHP, auto-commit mode is disabled by default for transaction management. It can be set by using cubrid_set_autocommit().

The following table shows the isolation levels from 1 to 6. It consists of table schema (row) and isolation level:

Levels of Isolation Supported by CUBRID
Name | Description
--- | ---
SERIALIZABLE (6) | In this isolation level, problems concerning concurrency (e.g. dirty read, non-repeatable read, phantom read, etc.) do not occur.
REPEATABLE READ CLASS with REPEATABLE READ INSTANCES (5) | Another transaction T2 cannot update the schema of table A while transaction T1 is viewing table A. Transaction T1 may experience phantom read for the record R that was inserted by another transaction T2 when it is repeatedly retrieving a specific record.
REPEATABLE READ CLASS with READ COMMITTED INSTANCES (or CURSOR STABILITY) (4) | Another transaction T2 cannot update the schema of table A while transaction T1 is viewing table A. Transaction T1 may experience R read (non-repeatable read) that was updated and committed by another transaction T2 when it is repeatedly retrieving the record R.
REPEATABLE READ CLASS with READ UNCOMMITTED INSTANCES (3) | Default isolation level. Another transaction T2 cannot update the schema of table A while transaction T1 is viewing table A. Transaction T1 may experience R' read (dirty read) for the record that was updated but not committed by another transaction T2.
READ COMMITTED CLASS with READ COMMITTED INSTANCES (2) | Transaction T1 may experience A' read (non-repeatable read) for the table that was updated and committed by another transaction T2 while it is viewing table A repeatedly. Transaction T1 may experience R' read (non-repeatable read) for the record that was updated and committed by another transaction T2 while it is retrieving the record R repeatedly.
READ COMMITTED CLASS with READ UNCOMMITTED INSTANCES (1) | Transaction T1 may experience A' read (non-repeatable read) for the table that was updated and committed by another transaction T2 while it is repeatedly viewing table A. Transaction T1 may experience R' read (dirty read) for the record that was updated but not committed by another transaction T2.

### 参数

`conn_identifier`

  The CUBRID connection. If the connection identifier is not specified, the last link opened by cubrid_connect() is assumed.

### 返回值

An associative array with CUBRID database parameters; on success.

`FALSE` on failure.

### 更新日志

版本 | 说明
--- | ---
8.4.0 | Change LOCK_TIMEOUT to PARAM_LOCK_TIMEOUT, and MAX_STRING_LENGTH to PARAM_MAX_STRING_LENGTH in result.

### 范例

Example #1 cubrid_get_db_parameter() example

    <?php
    printf("%-30s %s\n", "CUBRID PHP Version:", cubrid_version());

    printf("\n");

    $conn = cubrid_connect("localhost", 33088, "demodb");

    if (!$conn) {
        die('Connect Error ('. cubrid_error_code() .')' . cubrid_error_msg());
    }

    $db_params = cubrid_get_db_parameter($conn);

    while (list($param_name, $param_value) = each($db_params)) {
        printf("%-30s %s\n", $param_name, $param_value);
    }

    printf("\n");

    $server_info = cubrid_get_server_info($conn);
    $client_info = cubrid_get_client_info();

    printf("%-30s %s\n", "Server Info:", $server_info);
    printf("%-30s %s\n", "Client Info:", $client_info);

    printf("\n");

    $charset = cubrid_get_charset($conn);

    printf("%-30s %s\n", "CUBRID Charset:", $charset);

    cubrid_disconnect($conn);

    ?>

以上例程会输出：

    CUBRID PHP Version:            9.1.0.0001

    PARAM_ISOLATION_LEVEL          3
    LOCK_TIMEOUT                   -1
    MAX_STRING_LENGTH              1073741823
    PARAM_AUTO_COMMIT              1

    Server Info:                   9.1.0.0212
    Client Info:                   9.1.0

    CUBRID Charset:                iso8859-1

### 参见

- cubrid_set_db_parameter() - Sets the CUBRID database parameters
- cubrid_get_autocommit() - Get auto-commit mode of the connection