ddl-manager/dist/ast/OrderByItem.js

store postgres procedures and triggers in files

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.OrderByItem = void 0;
const AbstractAstElement_1 = require("./AbstractAstElement");
const expression_1 = require("./expression");
class OrderByItem extends AbstractAstElement_1.AbstractAstElement {
    constructor(params) {
        super();
        this.expression = params.expression;
        this.type = params.type || "asc";
        // https://postgrespro.ru/docs/postgrespro/10/queries-order
        // По умолчанию значения NULL считаются больше любых других, 
        this.nulls = (params.nulls || (
        // то есть подразумевается NULLS FIRST для порядка DESC и 
        this.type === "desc" ?
            "first" :
            // NULLS LAST в противном случае.
            "last"));
    }
    clone() {
        return new OrderByItem({
            expression: this.expression.clone(),
            type: this.type,
            nulls: this.nulls
        });
    }
    replaceTable(replaceTable, toTable) {
        return new OrderByItem({
            expression: this.expression
                .replaceTable(replaceTable, toTable),
            type: this.type,
            nulls: this.nulls
        });
    }
    equal(item) {
        return (this.expression.equal(item.expression) &&
            this.type == item.type &&
            this.nulls == item.nulls);
    }
    getColumnReferences() {
        return this.expression.getColumnReferences();
    }
    template(spaces) {
        return [
            this.expression.toSQL(spaces) +
                " " + this.type +
                " nulls " + this.nulls
        ];
    }
    getFirstColumnRef() {
        return this.getColumnReferences()[0];
    }
    isIdSort() {
        return (this.expression.isColumnReference() &&
            this.getFirstColumnRef().name === "id");
    }
    compareRowsByOrder(leftRow, vector, rightRow, orPreConditions) {
        const operator = (this.type === "asc" && vector === "above" ||
            this.type === "desc" && vector === "below") ? "<" : ">";
        if (typeof leftRow === "string") {
            const rowName = leftRow;
            leftRow = (columnName) => `${rowName}.${columnName}`;
        }
        if (typeof rightRow === "string") {
            const rowName = rightRow;
            rightRow = (columnName) => `${rowName}.${columnName}`;
        }
        return expression_1.Expression.or([
            ...orPreConditions,
            expression_1.Expression.and([
                `${this.printRowValue(leftRow)} is not distinct from ${this.printRowValue(rightRow)}`,
                `${leftRow("id")} ${operator} ${rightRow("id")}`
            ]),
            this.compareRowsNulls(leftRow, vector, rightRow),
            `${this.printRowValue(leftRow)} ${operator} ${this.printRowValue(rightRow)}`
        ]);
    }
    compareRowsNulls(leftRow, vector, rightRow) {
        let conditions = [];
        // https://postgrespro.ru/docs/postgrespro/10/queries-order
        // По умолчанию значения NULL считаются больше любых других, 
        const leftShouldBeNull = (vector === "above" && this.nulls === "first"
            ||
                vector === "below" && this.nulls === "last");
        if (leftShouldBeNull) {
            conditions = [
                `${this.printRowValue(leftRow)} is null`,
                `${this.printRowValue(rightRow)} is not null`
            ];
        }
        else {
            conditions = [
                `${this.printRowValue(leftRow)} is not null`,
                `${this.printRowValue(rightRow)} is null`
            ];
        }
        return expression_1.Expression.and(conditions);
    }
    printRowValue(row) {
        let expression = this.expression;
        for (const columnRef of this.getColumnReferences()) {
            expression = expression.replaceColumn(columnRef, expression_1.Expression.unknown(row(columnRef.name)));
        }
        return expression.toString();
    }
}
exports.OrderByItem = OrderByItem;
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