This shows you the differences between two versions of the page.
— |
max-part-date [2015/09/23 20:27] (current) |
||
---|---|---|---|
Line 1: | Line 1: | ||
+ | ====== MAX_PART_DATE Function - PL/HQL ====== | ||
+ | MAX_PART_DATE function finds the maximum value for the specified partition column of type DATE. | ||
+ | |||
+ | **Syntax**: | ||
+ | |||
+ | <code language="sql"> | ||
+ | MAX_PART_DATE([db_name.]table_name [, column_name [, part_col=filter, ...]]); | ||
+ | </code> | ||
+ | |||
+ | **Parameters:** | ||
+ | |||
+ | | **Parameter** | **Type** | **Value** | **Description** | | ||
+ | | [dbname.]table_name | VARCHAR | Identifier, variable or expression | Table name | | ||
+ | | column_name | VARCHAR | Identifier, variable or expression | Partition column name | | ||
+ | | part_col=filter | | | Partition filter | | ||
+ | |||
+ | **Notes**: | ||
+ | |||
+ | * If column name is not specified, the first partition column is used | ||
+ | * Partition filter applied before finding the maximum value | ||
+ | |||
+ | **Return Value:** | ||
+ | |||
+ | * The maximum date for the specified partition | ||
+ | * NULL if the table or partition do not exist, or the table is empty | ||
+ | |||
+ | **Return Type:** | ||
+ | |||
+ | DATE. | ||
+ | |||
+ | **Example 1:** | ||
+ | |||
+ | Table //db.orders// is partitioned by //local_date// and has the following partitions: | ||
+ | |||
+ | | local_date=2014-12-02 | | ||
+ | | local_date=2014-12-03 | | ||
+ | | local_date=2014-12-04 | | ||
+ | |||
+ | Find the maximum value of the partition: | ||
+ | |||
+ | <code language="sql"> | ||
+ | MAX_PART_DATE(db.orders); | ||
+ | </code> | ||
+ | |||
+ | Result: 2014-12-04 | ||
+ | |||
+ | **Example 2:** | ||
+ | |||
+ | Table //db.sales// is partitioned by //country// and //local_date// and has the following partitions: | ||
+ | |||
+ | | country=US/local_date=2014-12-02 | | ||
+ | | country=US/local_date=2014-12-03 | | ||
+ | | country=UK/local_date=2014-12-04 | | ||
+ | |||
+ | Find the maximum value for //local_date// partition column for country US: | ||
+ | |||
+ | <code language="sql"> | ||
+ | MAX_PART_DATE(db.sales, local_date, country='US'); | ||
+ | </code> | ||
+ | |||
+ | Result: 2014-12-03 | ||
+ | |||
+ | **Compatibility**: PL/HQL extension. | ||
+ | |||
+ | **Version:** PL/HQL 0.01 | ||
+ | |||
+ | See also: | ||
+ | |||
+ | * [[min-part-date|MIN_PART_DATE(table, colname, partition_spec)]] | ||
+ | * [[max-part-string|MAX_PART_STRING(table, colname, partition_spec)]] | ||
+ | * [[min-part-string|MIN_PART_STRING(table, colname, partition_spec)]] | ||
+ | * [[max-part-int|MAX_PART_INT(table, colname, partition_spec)]] | ||
+ | * [[min-part-int|MIN_PART_INT(table, colname, partition_spec)]] |