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Sequence

Overview

The provided TypeScript module Sequence provides methods for interacting with sequences in a database. Here's an explanation of the key components:

Sequence Class:

The `Sequence`` class provides static methods for working with database sequences.

Methods

nextval

nextval(sequence: string, tableName?: string, datasourceName?: string): number

Retrieves the next value from the specified sequence.

Parameters:

  • sequence: The name of the sequence.
  • tableName: (Optional) The name of the table associated with the sequence.
  • datasourceName: (Optional) The name of the data source.
  • Return Value: The next value from the specified sequence.

create

create(sequence: string, start?: number, datasourceName?: string): void

Creates a new sequence with the specified name and optional starting value.

Parameters:

  • sequence: The name of the sequence to be created.
  • start: (Optional) The starting value of the sequence. Defaults to 1 if not provided.
  • datasourceName: (Optional) The name of the data source.
  • Return Value: None.

drop

drop(sequence: string, datasourceName?: string): void

Drops (deletes) the specified sequence.

Parameters:

  • sequence: The name of the sequence to be dropped.
  • datasourceName: (Optional) The name of the data source.
  • Return Value: None.

Example Usage:

import { Sequence } from 'sdk/db/sequence';

// Example sequence name
const sequenceName = 'your_sequence';

// Retrieve the next value from the sequence
const nextValue = Sequence.nextval(sequenceName);
console.log('Next Value:', nextValue);

// Create a new sequence with the specified name and starting value
Sequence.create(sequenceName, 100, datasourceName);

// Drop (delete) the specified sequence
Sequence.drop(sequenceName, datasourceName);

Replace your_sequence, and other placeholders with your actual module path, sequence name, table name, data source, and sequence details.

Functions

Function Description Returns
nextval(name, databaseType?, datasourceName?) Increment the sequence with the given name and returns the value. Creates the sequence implicitly if it deos not exist. integer
create(name, databaseType?, datasourceName?) Creates the sequence by the given name. -
drop(name, databaseType?, datasourceName?) Remove the sequence by the given name. -