EntityMetadata.ts

import {QueryRunner, SelectQueryBuilder} from "..";
import {ObjectLiteral} from "../common/ObjectLiteral";
import {Connection} from "../connection/Connection";
import {PostgresConnectionOptions} from "../driver/postgres/PostgresConnectionOptions";
import {PostgresDriver} from "../driver/postgres/PostgresDriver";
import {SapDriver} from "../driver/sap/SapDriver";
import {SqlServerConnectionOptions} from "../driver/sqlserver/SqlServerConnectionOptions";
import {SqlServerDriver} from "../driver/sqlserver/SqlServerDriver";
import {CannotCreateEntityIdMapError} from "../error/CannotCreateEntityIdMapError";
import {OrderByCondition} from "../find-options/OrderByCondition";
import {TableMetadataArgs} from "../metadata-args/TableMetadataArgs";
import {TreeMetadataArgs} from "../metadata-args/TreeMetadataArgs";
import {OrmUtils} from "../util/OrmUtils";
import {shorten} from "../util/StringUtils";
import {CheckMetadata} from "./CheckMetadata";
import {ColumnMetadata} from "./ColumnMetadata";
import {EmbeddedMetadata} from "./EmbeddedMetadata";
import {EntityListenerMetadata} from "./EntityListenerMetadata";
import {ExclusionMetadata} from "./ExclusionMetadata";
import {ForeignKeyMetadata} from "./ForeignKeyMetadata";
import {IndexMetadata} from "./IndexMetadata";
import {RelationCountMetadata} from "./RelationCountMetadata";
import {RelationIdMetadata} from "./RelationIdMetadata";
import {RelationMetadata} from "./RelationMetadata";
import {TableType} from "./types/TableTypes";
import {TreeType} from "./types/TreeTypes";
import {UniqueMetadata} from "./UniqueMetadata";

/**
 * Contains all entity metadata.
 */
export class EntityMetadata {

    // -------------------------------------------------------------------------
    // Properties
    // -------------------------------------------------------------------------

    /**
     * Connection where this entity metadata is created.
     */
    connection: Connection;

    /**
     * Metadata arguments used to build this entity metadata.
     */
    tableMetadataArgs: TableMetadataArgs;

    /**
     * If entity's table is a closure-typed table, then this entity will have a closure junction table metadata.
     */
    closureJunctionTable: EntityMetadata;

    /**
     * If this is entity metadata for a junction closure table then its owner closure table metadata will be set here.
     */
    parentClosureEntityMetadata: EntityMetadata;

    /**
     * Parent's entity metadata. Used in inheritance patterns.
     */
    parentEntityMetadata: EntityMetadata;

    /**
     * Children entity metadatas. Used in inheritance patterns.
     */
    childEntityMetadatas: EntityMetadata[] = [];

    /**
     * All "inheritance tree" from a target entity.
     * For example for target Post < ContentModel < Unit it will be an array of [Post, ContentModel, Unit].
     * It also contains child entities for single table inheritance.
     */
    inheritanceTree: Function[] = [];

    /**
     * Table type. Tables can be abstract, closure, junction, embedded, etc.
     */
    tableType: TableType = "regular";

    /**
     * Target class to which this entity metadata is bind.
     * Note, that when using table inheritance patterns target can be different rather then table's target.
     * For virtual tables which lack of real entity (like junction tables) target is equal to their table name.
     */
    target: Function|string;

    /**
     * Gets the name of the target.
     */
    targetName: string;

    /**
     * Entity's name.
     * Equal to entity target class's name if target is set to table.
     * If target class is not then then it equals to table name.
     */
    name: string;

    /**
     * View's expression.
     * Used in views
     */
    expression?: string|((connection: Connection) => SelectQueryBuilder<any>);

    /**
     * Enables Sqlite "WITHOUT ROWID" modifier for the "CREATE TABLE" statement
     */
    withoutRowid?: boolean = false;

    /**
     * Original user-given table name (taken from schema or @Entity(tableName) decorator).
     * If user haven't specified a table name this property will be undefined.
     */
    givenTableName?: string;

    /**
     * Entity table name in the database.
     * This is final table name of the entity.
     * This name already passed naming strategy, and generated based on
     * multiple criteria, including user table name and global table prefix.
     */
    tableName: string;

    /**
     * Entity table path. Contains database name, schema name and table name.
     * E.g. myDB.mySchema.myTable
     */
    tablePath: string;

    /**
     * Entity schema path. Contains database name and schema name.
     * E.g. myDB.mySchema
     */
    schemaPath?: string;

    /**
     * Gets the table name without global table prefix.
     * When querying table you need a table name with prefix, but in some scenarios,
     * for example when you want to name a junction table that contains names of two other tables,
     * you may want a table name without prefix.
     */
    tableNameWithoutPrefix: string;

    /**
     * Indicates if schema will be synchronized for this entity or not.
     */
    synchronize: boolean = true;

    /**
     * Table's database engine type (like "InnoDB", "MyISAM", etc).
     */
    engine?: string;

    /**
     * Database name.
     */
    database?: string;

    /**
     * Schema name. Used in Postgres and Sql Server.
     */
    schema?: string;

    /**
     * Specifies a default order by used for queries from this table when no explicit order by is specified.
     */
    orderBy?: OrderByCondition;

    /**
     * If this entity metadata's table using one of the inheritance patterns,
     * then this will contain what pattern it uses.
     */
    inheritancePattern?: "STI"/*|"CTI"*/;

    /**
     * Checks if there any non-nullable column exist in this entity.
     */
    hasNonNullableRelations: boolean = false;

    /**
     * Indicates if this entity metadata of a junction table, or not.
     * Junction table is a table created by many-to-many relationship.
     *
     * Its also possible to understand if entity is junction via tableType.
     */
    isJunction: boolean = false;

    /**
     * Indicates if this entity is a tree, what type of tree it is.
     */
    treeType?: TreeType;

    /**
     * Checks if this table is a junction table of the closure table.
     * This type is for tables that contain junction metadata of the closure tables.
     */
    isClosureJunction: boolean = false;

    /**
     * Checks if entity's table has multiple primary columns.
     */
    hasMultiplePrimaryKeys: boolean = false;

    /**
     * Indicates if this entity metadata has uuid generated columns.
     */
    hasUUIDGeneratedColumns: boolean = false;

    /**
     * If this entity metadata is a child table of some table, it should have a discriminator value.
     * Used to store a value in a discriminator column.
     */
    discriminatorValue?: string;

    /**
     * Entity's column metadatas defined by user.
     */
    ownColumns: ColumnMetadata[] = [];

    /**
     * Columns of the entity, including columns that are coming from the embeddeds of this entity.
     */
    columns: ColumnMetadata[] = [];

    /**
     * Ancestor columns used only in closure junction tables.
     */
    ancestorColumns: ColumnMetadata[] = [];

    /**
     * Descendant columns used only in closure junction tables.
     */
    descendantColumns: ColumnMetadata[] = [];

    /**
     * All columns except for virtual columns.
     */
    nonVirtualColumns: ColumnMetadata[] = [];

    /**
     * In the case if this entity metadata is junction table's entity metadata,
     * this will contain all referenced columns of owner entity.
     */
    ownerColumns: ColumnMetadata[] = [];

    /**
     * In the case if this entity metadata is junction table's entity metadata,
     * this will contain all referenced columns of inverse entity.
     */
    inverseColumns: ColumnMetadata[] = [];

    /**
     * Gets the column with generated flag.
     */
    generatedColumns: ColumnMetadata[] = [];

    /**
     * Gets the object id column used with mongodb database.
     */
    objectIdColumn?: ColumnMetadata;

    /**
     * Gets entity column which contains a create date value.
     */
    createDateColumn?: ColumnMetadata;

    /**
     * Gets entity column which contains an update date value.
     */
    updateDateColumn?: ColumnMetadata;

    /**
     * Gets entity column which contains an entity version.
     */
    versionColumn?: ColumnMetadata;

    /**
     * Gets the discriminator column used to store entity identificator in single-table inheritance tables.
     */
    discriminatorColumn?: ColumnMetadata;

    /**
     * Special column that stores tree level in tree entities.
     */
    treeLevelColumn?: ColumnMetadata;

    /**
     * Nested set's left value column.
     * Used only in tree entities with nested set pattern applied.
     */
    nestedSetLeftColumn?: ColumnMetadata;

    /**
     * Nested set's right value column.
     * Used only in tree entities with nested set pattern applied.
     */
    nestedSetRightColumn?: ColumnMetadata;

    /**
     * Materialized path column.
     * Used only in tree entities with materialized path pattern applied.
     */
    materializedPathColumn?: ColumnMetadata;

    /**
     * Gets the primary columns.
     */
    primaryColumns: ColumnMetadata[] = [];

    /**
     * Entity's relation metadatas.
     */
    ownRelations: RelationMetadata[] = [];

    /**
     * Relations of the entity, including relations that are coming from the embeddeds of this entity.
     */
    relations: RelationMetadata[] = [];

    /**
     * List of eager relations this metadata has.
     */
    eagerRelations: RelationMetadata[] = [];

    /**
     * List of eager relations this metadata has.
     */
    lazyRelations: RelationMetadata[] = [];

    /**
     * Gets only one-to-one relations of the entity.
     */
    oneToOneRelations: RelationMetadata[] = [];

    /**
     * Gets only owner one-to-one relations of the entity.
     */
    ownerOneToOneRelations: RelationMetadata[] = [];

    /**
     * Gets only one-to-many relations of the entity.
     */
    oneToManyRelations: RelationMetadata[] = [];

    /**
     * Gets only many-to-one relations of the entity.
     */
    manyToOneRelations: RelationMetadata[] = [];

    /**
     * Gets only many-to-many relations of the entity.
     */
    manyToManyRelations: RelationMetadata[] = [];

    /**
     * Gets only owner many-to-many relations of the entity.
     */
    ownerManyToManyRelations: RelationMetadata[] = [];

    /**
     * Gets only owner one-to-one and many-to-one relations.
     */
    relationsWithJoinColumns: RelationMetadata[] = [];

    /**
     * Tree parent relation. Used only in tree-tables.
     */
    treeParentRelation?: RelationMetadata;

    /**
     * Tree children relation. Used only in tree-tables.
     */
    treeChildrenRelation?: RelationMetadata;

    /**
     * Entity's relation id metadatas.
     */
    relationIds: RelationIdMetadata[] = [];

    /**
     * Entity's relation id metadatas.
     */
    relationCounts: RelationCountMetadata[] = [];

    /**
     * Entity's foreign key metadatas.
     */
    foreignKeys: ForeignKeyMetadata[] = [];

    /**
     * Entity's embedded metadatas.
     */
    embeddeds: EmbeddedMetadata[] = [];

    /**
     * All embeddeds - embeddeds from this entity metadata and from all child embeddeds, etc.
     */
    allEmbeddeds: EmbeddedMetadata[] = [];

    /**
     * Entity's own indices.
     */
    ownIndices: IndexMetadata[] = [];

    /**
     * Entity's index metadatas.
     */
    indices: IndexMetadata[] = [];

    /**
     * Entity's unique metadatas.
     */
    uniques: UniqueMetadata[] = [];

    /**
     * Entity's own uniques.
     */
    ownUniques: UniqueMetadata[] = [];

    /**
     * Entity's check metadatas.
     */
    checks: CheckMetadata[] = [];

    /**
     * Entity's exclusion metadatas.
     */
    exclusions: ExclusionMetadata[] = [];

    /**
     * Entity's own listener metadatas.
     */
    ownListeners: EntityListenerMetadata[] = [];

    /**
     * Entity listener metadatas.
     */
    listeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER LOAD" type.
     */
    afterLoadListeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER INSERT" type.
     */
    beforeInsertListeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER INSERT" type.
     */
    afterInsertListeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER UPDATE" type.
     */
    beforeUpdateListeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER UPDATE" type.
     */
    afterUpdateListeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER REMOVE" type.
     */
    beforeRemoveListeners: EntityListenerMetadata[] = [];

    /**
     * Listener metadatas with "AFTER REMOVE" type.
     */
    afterRemoveListeners: EntityListenerMetadata[] = [];

    /**
     * Map of columns and relations of the entity.
     *
     * example: Post{ id: number, name: string, counterEmbed: { count: number }, category: Category }.
     * This method will create following object:
     * { id: "id", counterEmbed: { count: "counterEmbed.count" }, category: "category" }
     */
    propertiesMap: ObjectLiteral;

    // ---------------------------------------------------------------------
    // Constructor
    // ---------------------------------------------------------------------

    constructor(options: {
        connection: Connection,
        inheritanceTree?: Function[],
        inheritancePattern?: "STI"/*|"CTI"*/,
        tableTree?: TreeMetadataArgs,
        parentClosureEntityMetadata?: EntityMetadata,
        args: TableMetadataArgs
    }) {
        this.connection = options.connection;
        this.inheritanceTree = options.inheritanceTree || [];
        this.inheritancePattern = options.inheritancePattern;
        this.treeType = options.tableTree ? options.tableTree.type : undefined;
        this.parentClosureEntityMetadata = options.parentClosureEntityMetadata!;
        this.tableMetadataArgs = options.args;
        this.target = this.tableMetadataArgs.target;
        this.tableType = this.tableMetadataArgs.type;
        this.expression = this.tableMetadataArgs.expression;
        this.withoutRowid = this.tableMetadataArgs.withoutRowid;
    }

    // -------------------------------------------------------------------------
    // Public Methods
    // -------------------------------------------------------------------------

    /**
     * Creates a new entity.
     */
    create(queryRunner?: QueryRunner): any {
        // if target is set to a function (e.g. class) that can be created then create it
        let ret: any;
        if (this.target instanceof Function) {
            ret = new (<any> this.target)();
            this.lazyRelations.forEach(relation => this.connection.relationLoader.enableLazyLoad(relation, ret, queryRunner));
            return ret;
        }

        // otherwise simply return a new empty object
        const newObject = {};
        this.lazyRelations.forEach(relation => this.connection.relationLoader.enableLazyLoad(relation, newObject, queryRunner));
        return newObject;
    }

    /**
     * Checks if given entity has an id.
     */
    hasId(entity: ObjectLiteral): boolean {
        if (!entity)
            return false;

        return this.primaryColumns.every(primaryColumn => {
            const value = primaryColumn.getEntityValue(entity);
            return value !== null && value !== undefined && value !== "";
        });
    }

    /**
     * Checks if given entity / object contains ALL primary keys entity must have.
     * Returns true if it contains all of them, false if at least one of them is not defined.
     */
    hasAllPrimaryKeys(entity: ObjectLiteral): boolean {
        return this.primaryColumns.every(primaryColumn => {
            const value = primaryColumn.getEntityValue(entity);
            return value !== null && value !== undefined;
        });
    }

    /**
     * Ensures that given object is an entity id map.
     * If given id is an object then it means its already id map.
     * If given id isn't an object then it means its a value of the id column
     * and it creates a new id map with this value and name of the primary column.
     */
    ensureEntityIdMap(id: any): ObjectLiteral {
        if (id instanceof Object)
            return id;

        if (this.hasMultiplePrimaryKeys)
            throw new CannotCreateEntityIdMapError(this, id);

        return this.primaryColumns[0].createValueMap(id);
    }

    /**
     * Gets primary keys of the entity and returns them in a literal object.
     * For example, for Post{ id: 1, title: "hello" } where id is primary it will return { id: 1 }
     * For multiple primary keys it returns multiple keys in object.
     * For primary keys inside embeds it returns complex object literal with keys in them.
     */
    getEntityIdMap(entity: ObjectLiteral|undefined): ObjectLiteral|undefined {
        if (!entity)
            return undefined;

        return EntityMetadata.getValueMap(entity, this.primaryColumns, { skipNulls: true });
    }

    /**
     * Creates a "mixed id map".
     * If entity has multiple primary keys (ids) then it will return just regular id map, like what getEntityIdMap returns.
     * But if entity has a single primary key then it will return just value of the id column of the entity, just value.
     * This is called mixed id map.
     */
    getEntityIdMixedMap(entity: ObjectLiteral|undefined): ObjectLiteral|undefined {
        if (!entity)
            return entity;

        const idMap = this.getEntityIdMap(entity);
        if (this.hasMultiplePrimaryKeys) {
            return idMap;

        } else if (idMap) {
            return this.primaryColumns[0].getEntityValue(idMap); // todo: what about parent primary column?
        }

        return idMap;
    }

    /**
     * Compares two different entities by their ids.
     * Returns true if they match, false otherwise.
     */
    compareEntities(firstEntity: ObjectLiteral, secondEntity: ObjectLiteral): boolean {

        const firstEntityIdMap = this.getEntityIdMap(firstEntity);
        if (!firstEntityIdMap) return false;

        const secondEntityIdMap = this.getEntityIdMap(secondEntity);
        if (!secondEntityIdMap) return false;

        return EntityMetadata.compareIds(firstEntityIdMap, secondEntityIdMap);
    }

    /**
     * Finds column with a given property name.
     */
    findColumnWithPropertyName(propertyName: string): ColumnMetadata|undefined {
        return this.columns.find(column => column.propertyName === propertyName);
    }

    /**
     * Finds column with a given database name.
     */
    findColumnWithDatabaseName(databaseName: string): ColumnMetadata|undefined {
        return this.columns.find(column => column.databaseName === databaseName);
    }

    /**
     * Finds column with a given property path.
     */
    findColumnWithPropertyPath(propertyPath: string): ColumnMetadata|undefined {
        const column = this.columns.find(column => column.propertyPath === propertyPath);
        if (column)
            return column;

        // in the case if column with property path was not found, try to find a relation with such property path
        // if we find relation and it has a single join column then its the column user was seeking
        const relation = this.relations.find(relation => relation.propertyPath === propertyPath);
        if (relation && relation.joinColumns.length === 1)
            return relation.joinColumns[0];

        return undefined;
    }

    /**
     * Finds columns with a given property path.
     * Property path can match a relation, and relations can contain multiple columns.
     */
    findColumnsWithPropertyPath(propertyPath: string): ColumnMetadata[] {
        const column = this.columns.find(column => column.propertyPath === propertyPath);
        if (column)
            return [column];

        // in the case if column with property path was not found, try to find a relation with such property path
        // if we find relation and it has a single join column then its the column user was seeking
        const relation = this.relations.find(relation => relation.propertyPath === propertyPath);
        if (relation && relation.joinColumns)
            return relation.joinColumns;

        return [];
    }

    /**
     * Finds relation with the given property path.
     */
    findRelationWithPropertyPath(propertyPath: string): RelationMetadata|undefined {
        return this.relations.find(relation => relation.propertyPath === propertyPath);
    }

    /**
     * Checks if there is an embedded with a given property path.
     */
    hasEmbeddedWithPropertyPath(propertyPath: string): boolean {
        return this.allEmbeddeds.some(embedded => embedded.propertyPath === propertyPath);
    }

    /**
     * Finds embedded with a given property path.
     */
    findEmbeddedWithPropertyPath(propertyPath: string): EmbeddedMetadata|undefined {
        return this.allEmbeddeds.find(embedded => embedded.propertyPath === propertyPath);
    }

    /**
     * Iterates through entity and finds and extracts all values from relations in the entity.
     * If relation value is an array its being flattened.
     */
    extractRelationValuesFromEntity(entity: ObjectLiteral, relations: RelationMetadata[]): [RelationMetadata, any, EntityMetadata][] {
        const relationsAndValues: [RelationMetadata, any, EntityMetadata][] = [];
        relations.forEach(relation => {
            const value = relation.getEntityValue(entity);
            if (value instanceof Array) {
                value.forEach(subValue => relationsAndValues.push([relation, subValue, relation.inverseEntityMetadata]));
            } else if (value) {
                relationsAndValues.push([relation, value, relation.inverseEntityMetadata]);
            }
        });
        return relationsAndValues;
    }

    // -------------------------------------------------------------------------
    // Public Static Methods
    // -------------------------------------------------------------------------

    /**
     * Creates a property paths for a given entity.
     */
    static createPropertyPath(metadata: EntityMetadata, entity: ObjectLiteral, prefix: string = "") {
        const paths: string[] = [];
        Object.keys(entity).forEach(key => {

            // check for function is needed in the cases when createPropertyPath used on values containg a function as a value
            // example: .update().set({ name: () => `SUBSTR('', 1, 2)` })
            const parentPath = prefix ? prefix + "." + key : key;
            if (metadata.hasEmbeddedWithPropertyPath(parentPath)) {
                const subPaths = this.createPropertyPath(metadata, entity[key], parentPath);
                paths.push(...subPaths);
            } else {
                const path = prefix ? prefix + "." + key : key;
                paths.push(path);
            }
        });
        return paths;
    }

    /**
     * Finds difference between two entity id maps.
     * Returns items that exist in the first array and absent in the second array.
     */
    static difference(firstIdMaps: ObjectLiteral[], secondIdMaps: ObjectLiteral[]): ObjectLiteral[] {
        return firstIdMaps.filter(firstIdMap => {
            return !secondIdMaps.find(secondIdMap => OrmUtils.deepCompare(firstIdMap, secondIdMap));
        });
    }

    /**
     * Compares ids of the two entities.
     * Returns true if they match, false otherwise.
     */
    static compareIds(firstId: ObjectLiteral|undefined, secondId: ObjectLiteral|undefined): boolean {
        if (firstId === undefined || firstId === null || secondId === undefined || secondId === null)
            return false;

        return OrmUtils.deepCompare(firstId, secondId);
    }

    /**
     * Creates value map from the given values and columns.
     * Examples of usages are primary columns map and join columns map.
     */
    static getValueMap(entity: ObjectLiteral, columns: ColumnMetadata[], options?: { skipNulls?: boolean }): ObjectLiteral|undefined {
        return columns.reduce((map, column) => {
            const value = column.getEntityValueMap(entity, options);

            // make sure that none of the values of the columns are not missing
            if (map === undefined || value === null || value === undefined)
                return undefined;

            return column.isObjectId ? Object.assign(map, value) : OrmUtils.mergeDeep(map, value);
        }, {} as ObjectLiteral|undefined);
    }

    // ---------------------------------------------------------------------
    // Public Builder Methods
    // ---------------------------------------------------------------------

    build() {
        const namingStrategy = this.connection.namingStrategy;
        const entityPrefix = this.connection.options.entityPrefix;
        this.engine = this.tableMetadataArgs.engine;
        this.database = this.tableMetadataArgs.type === "entity-child" && this.parentEntityMetadata ? this.parentEntityMetadata.database : this.tableMetadataArgs.database;
        if (this.tableMetadataArgs.schema) {
            this.schema = this.tableMetadataArgs.schema;
        }
        else if ((this.tableMetadataArgs.type === "entity-child") && this.parentEntityMetadata) {
            this.schema = this.parentEntityMetadata.schema;
        }
        else {
            this.schema = (this.connection.options as PostgresConnectionOptions|SqlServerConnectionOptions).schema;
        }
        this.givenTableName = this.tableMetadataArgs.type === "entity-child" && this.parentEntityMetadata ? this.parentEntityMetadata.givenTableName : this.tableMetadataArgs.name;
        this.synchronize = this.tableMetadataArgs.synchronize === false ? false : true;
        this.targetName = this.tableMetadataArgs.target instanceof Function ? (this.tableMetadataArgs.target as any).name : this.tableMetadataArgs.target;
        if (this.tableMetadataArgs.type === "closure-junction") {
            this.tableNameWithoutPrefix = namingStrategy.closureJunctionTableName(this.givenTableName!);
        } else if (this.tableMetadataArgs.type === "entity-child" && this.parentEntityMetadata) {
            this.tableNameWithoutPrefix = namingStrategy.tableName(this.parentEntityMetadata.targetName, this.parentEntityMetadata.givenTableName);
        } else {
            this.tableNameWithoutPrefix = namingStrategy.tableName(this.targetName, this.givenTableName);

            if (this.connection.driver.maxAliasLength && this.connection.driver.maxAliasLength > 0 && this.tableNameWithoutPrefix.length > this.connection.driver.maxAliasLength) {
                this.tableNameWithoutPrefix = shorten(this.tableNameWithoutPrefix, { separator: "_", segmentLength: 3 });
            }
        }
        this.tableName = entityPrefix ? namingStrategy.prefixTableName(entityPrefix, this.tableNameWithoutPrefix) : this.tableNameWithoutPrefix;
        this.target = this.target ? this.target : this.tableName;
        this.name = this.targetName ? this.targetName : this.tableName;
        this.expression = this.tableMetadataArgs.expression;
        this.withoutRowid = this.tableMetadataArgs.withoutRowid === true ? true : false;
        this.tablePath = this.buildTablePath();
        this.schemaPath = this.buildSchemaPath();
        this.orderBy = (this.tableMetadataArgs.orderBy instanceof Function) ? this.tableMetadataArgs.orderBy(this.propertiesMap) : this.tableMetadataArgs.orderBy; // todo: is propertiesMap available here? Looks like its not

        this.isJunction = this.tableMetadataArgs.type === "closure-junction" || this.tableMetadataArgs.type === "junction";
        this.isClosureJunction = this.tableMetadataArgs.type === "closure-junction";
    }

    /**
     * Registers a new column in the entity and recomputes all depend properties.
     */
    registerColumn(column: ColumnMetadata) {
        if (this.ownColumns.indexOf(column) !== -1)
            return;

        this.ownColumns.push(column);
        this.columns = this.embeddeds.reduce((columns, embedded) => columns.concat(embedded.columnsFromTree), this.ownColumns);
        this.primaryColumns = this.columns.filter(column => column.isPrimary);
        this.hasMultiplePrimaryKeys = this.primaryColumns.length > 1;
        this.hasUUIDGeneratedColumns = this.columns.filter(column => column.isGenerated || column.generationStrategy === "uuid").length > 0;
        this.propertiesMap = this.createPropertiesMap();
        if (this.childEntityMetadatas)
            this.childEntityMetadatas.forEach(entityMetadata => entityMetadata.registerColumn(column));
    }

    /**
     * Creates a special object - all columns and relations of the object (plus columns and relations from embeds)
     * in a special format - { propertyName: propertyName }.
     *
     * example: Post{ id: number, name: string, counterEmbed: { count: number }, category: Category }.
     * This method will create following object:
     * { id: "id", counterEmbed: { count: "counterEmbed.count" }, category: "category" }
     */
    createPropertiesMap(): { [name: string]: string|any } {
        const map: { [name: string]: string|any } = {};
        this.columns.forEach(column => OrmUtils.mergeDeep(map, column.createValueMap(column.propertyPath)));
        this.relations.forEach(relation => OrmUtils.mergeDeep(map, relation.createValueMap(relation.propertyPath)));
        return map;
    }

    /**
     * Builds table path using database name, schema name and table name.
     */
    protected buildTablePath(): string {
        let tablePath = this.tableName;
        if (this.schema && ((this.connection.driver instanceof PostgresDriver) || (this.connection.driver instanceof SqlServerDriver) || (this.connection.driver instanceof SapDriver))) {
            tablePath = this.schema + "." + tablePath;
        }

        if (this.database && !(this.connection.driver instanceof PostgresDriver)) {
            if (!this.schema && this.connection.driver instanceof SqlServerDriver) {
                tablePath = this.database + ".." + tablePath;
            } else {
                tablePath = this.database + "." + tablePath;
            }
        }

        return tablePath;
    }

    /**
     * Builds table path using schema name and database name.
     */
    protected buildSchemaPath(): string|undefined {
        if (!this.schema)
            return undefined;

        return this.database && !(this.connection.driver instanceof PostgresDriver) ? this.database + "." + this.schema : this.schema;
    }

}