pg-structure / O2MRelation

# Class: O2MRelation

Class which represent one to many relationship which resembles hasMany relation in ORMs (Object Relational Mappers). Provides attributes and methods for details of the relationship.

Below is a database schema as an example:

Some definitions used in descriptions for O2MRelation.

** Source Table: ** Table which this relationship belongs to.
** Target Table: ** Table that is related to base table.

# Example

// Example tables have single primary key and examples first relation. So zero index ([0]) is used. Use all array elements if necessary.
// product ----< line_item
// (source)       (target)

const relation         = product.o2mRelations[0];              // RELATION:    product ---< line_item
const foreignKey       = relation.foreignKey;                  // FOREIGN KEY:          ^-- product_has_carts
const sourceTable      = relation.sourceTable;                 // TABLE:       product
const targetTable      = relation.targetTable;                 // TABLE:       line_item
const FKColumn         = relation.foreignKey.columns[0];       // COLUMN:      product_id  (from line_item table)
const sourcePKColumn   = relation.sourceTable.primaryKeys[0];  // COLUMN:      id          (from product table)

# Hierarchy

Relation

↳ O2MRelation

# Properties

# foreignKey

• foreignKey: ForeignKey

Foreign key between source table and target table.

# Example

const relation     = product.O2MRelationRelations[0];  // RELATION:    product ---< line_item
const foreignKey   = relation.foreignKey;              // CONSTRAINT:           ^-- product_has_carts
const FKColumn     = relation.foreignKey.columns[0];   // COLUMN:      product_id (from line_item table)

Defined in: pg-structure/relation/o2m-relation.ts:116

# toMany

• Readonly toMany: boolean= true

Whether the relation targets to many. Since, one to many relations targets many, this is true.

Defined in: pg-structure/relation/o2m-relation.ts:53

# type

• Readonly type: O2M

Type of the relation, which is o2m for O2MRelation. For TypeScript it is enum of RelationType.O2M.

Defined in: pg-structure/relation/o2m-relation.ts:48

# Accessors

# info

• get info(): string

Informational text representation of the relation.

# Example

const info = relation.info; // [public.contact]――― cart_contact ――⥷ [public.cart]

Returns: string

Defined in: pg-structure/relation/o2m-relation.ts:82

# name

• get name(): string

Suggested name for relation.

see {@link ../relation-names.md Relation Names}

Returns: string

Defined in: pg-structure/relation/o2m-relation.ts:61

# sourceAdjective

• get sourceAdjective(): undefined | string

Source table's adjective extracted from foreign key name.

Returns: undefined | string

Defined in: pg-structure/base/relation.ts:86

# sourceAlias

• get sourceAlias(): string

Source table alias

Returns: string

Defined in: pg-structure/relation/o2m-relation.ts:139

# sourceName

• get sourceName(): string

Source table name.

Returns: string

Defined in: pg-structure/base/relation.ts:76

# sourceTable

• get sourceTable(): Table

Table which this relation belongs to.

# Example

const relation     = product.O2MRelationRelations[0];  // RELATION:    product ---< line_item
const sourceTable  = relation.sourceTable;             // TABLE:       product

Returns: Table

Defined in: pg-structure/relation/o2m-relation.ts:93

# targetAdjective

• get targetAdjective(): undefined | string

Source table's adjective extracted from foreign key name.

Returns: undefined | string

Defined in: pg-structure/base/relation.ts:91

# targetAlias

• get targetAlias(): string

Target table alias

Returns: string

Defined in: pg-structure/relation/o2m-relation.ts:144

# targetName

• get targetName(): string

Target table name

Returns: string

Defined in: pg-structure/base/relation.ts:81

# targetTable

• get targetTable(): Table

Table which this relation is referring to.

# Example

const relation     = product.O2MRelationRelations[0];  // RELATION:    product ---< line_item
const targetTable  = relation.targetTable;             // TABLE:       line_item

Returns: Table

Defined in: pg-structure/relation/o2m-relation.ts:104

# Methods

# getName

▸ getName(relationNameFunctions: string | RelationNameFunctions): string

Retunrs name for the relation using given naming function.

# Parameters:

Name	Type	Description
`relationNameFunctions`	string \| RelationNameFunctions	are custom functions or name of the modulethat exports relation name functions to generate names with. `pg-structure` provides some builtin modules (`short`, `optimal` and `descriptive`), but you can use your own.

Returns: string

name for the relation using naming function.

Defined in: pg-structure/relation/o2m-relation.ts:72

# getSourceAliasWithout

▸ getSourceAliasWithout(without: any | source | target | RelationWithout[]): string

Returns source table alias after replacing given tables' names from it.

# Parameters:

Name	Type	Description
`without`	any \| source \| target \| RelationWithout[]	is type or types of tables to exclude names of.

Returns: string

source table alias after given tables' names replaced.

Defined in: pg-structure/relation/o2m-relation.ts:124

# getSourceNameWithout

▸ getSourceNameWithout(without: any | source | target | RelationWithout[]): string

Returns source table name after replacing given tables' names from it.

# Parameters:

Name	Type	Description
`without`	any \| source \| target \| RelationWithout[]	is type or types of tables to exclude names of.

Returns: string

source table name after given tables' names replaced.

Inherited from: Relation

Defined in: pg-structure/base/relation.ts:61

# getTargetAliasWithout

▸ getTargetAliasWithout(without: any | source | target | RelationWithout[]): string

Returns target table alias after replacing given tables' names from it.

# Parameters:

Name	Type	Description
`without`	any \| source \| target \| RelationWithout[]	is type or types of tables to exclude names of.

Returns: string

target table alias after given tables' names replaced.

Defined in: pg-structure/relation/o2m-relation.ts:134

# getTargetNameWithout

▸ getTargetNameWithout(without: any | source | target | RelationWithout[]): string

Returns target table name after replacing given tables' names from it.

# Parameters:

Name	Type	Description
`without`	any \| source \| target \| RelationWithout[]	is type or types of tables to exclude names of.

Returns: string

target table name after given tables' names replaced.

Inherited from: Relation

Defined in: pg-structure/base/relation.ts:71

← NormalFunction PrimaryKey →