Some TRQL date fns weren't working correctly

dateAdd() wasn’t being converted correctly to ClickHouse. We were getting a syntax error

Author: matt-aitken

internal-packages/tsql/src/query/printer.test.ts

@@ -1250,6 +1250,70 @@ describe("ClickHousePrinter", () => {
     });
   });
 
+  describe("Date functions with interval units", () => {
+    it("should output dateAdd with string interval as bare keyword", () => {
+      const { sql } = printQuery("SELECT dateAdd('day', 7, created_at) AS week_later FROM task_runs");
+
+      expect(sql).toContain("dateAdd(day, 7, created_at)");
+      expect(sql).not.toContain("'day'");
+    });
+
+    it("should output dateAdd with bare identifier interval as keyword", () => {
+      const { sql } = printQuery("SELECT dateAdd(day, 7, created_at) AS week_later FROM task_runs");
+
+      expect(sql).toContain("dateAdd(day, 7, created_at)");
+    });
+
+    it("should output dateDiff with string interval as bare keyword", () => {
+      const { sql } = printQuery(
+        "SELECT dateDiff('minute', started_at, completed_at) AS duration_minutes FROM task_runs"
+      );
+
+      expect(sql).toContain("dateDiff(minute,");
+      expect(sql).not.toContain("'minute'");
+    });
+
+    it("should output dateSub with string interval as bare keyword", () => {
+      const { sql } = printQuery("SELECT dateSub('hour', 1, created_at) AS earlier FROM task_runs");
+
+      expect(sql).toContain("dateSub(hour, 1, created_at)");
+      expect(sql).not.toContain("'hour'");
+    });
+
+    it("should output dateTrunc with string interval as bare keyword", () => {
+      const { sql } = printQuery(
+        "SELECT dateTrunc('month', created_at) AS month_start FROM task_runs"
+      );
+
+      expect(sql).toContain("dateTrunc(month, created_at)");
+      expect(sql).not.toContain("'month'");
+    });
+
+    it("should output date_add (underscore variant) with bare keyword", () => {
+      const { sql } = printQuery(
+        "SELECT date_add('week', 2, created_at) AS two_weeks FROM task_runs"
+      );
+
+      expect(sql).toContain("date_add(week, 2, created_at)");
+      expect(sql).not.toContain("'week'");
+    });
+
+    it("should output date_diff (underscore variant) with bare keyword", () => {
+      const { sql } = printQuery(
+        "SELECT date_diff('second', started_at, completed_at) AS dur FROM task_runs"
+      );
+
+      expect(sql).toContain("date_diff(second,");
+      expect(sql).not.toContain("'second'");
+    });
+
+    it("should handle case-insensitive interval units", () => {
+      const { sql } = printQuery("SELECT dateAdd('DAY', 7, created_at) AS week_later FROM task_runs");
+
+      expect(sql).toContain("dateAdd(day, 7, created_at)");
+    });
+  });
+
   describe("Tenant isolation", () => {
     it("should inject tenant guards for single table", () => {
       const context = createTestContext({

internal-packages/tsql/src/query/printer.ts

@@ -2926,7 +2926,7 @@ export class ClickHousePrinter {
     if (funcMeta) {
       validateFunctionArgs(node.args, funcMeta.minArgs, funcMeta.maxArgs, name);
 
-      const args = node.args.map((arg) => this.visit(arg));
+      const args = this.visitCallArgs(name, node.args);
       const params = node.params ? node.params.map((p) => this.visit(p)) : null;
       const paramsPart = params ? `(${params.join(", ")})` : "";
       return `${funcMeta.clickhouseName}${paramsPart}(${args.join(", ")})`;
@@ -2936,6 +2936,85 @@ export class ClickHousePrinter {
     throw new QueryError(`Unknown function: ${name}`);
   }
 
+  /**
+   * Valid ClickHouse interval unit keywords used by date functions like dateAdd, dateDiff, etc.
+   */
+  private static readonly INTERVAL_UNITS = new Set([
+    "second",
+    "minute",
+    "hour",
+    "day",
+    "week",
+    "month",
+    "quarter",
+    "year",
+  ]);
+
+  /**
+   * Date functions whose first argument is an interval unit keyword.
+   * ClickHouse requires the unit as a bare keyword (e.g., `dateAdd(day, 7, col)`),
+   * not a string literal (e.g., `dateAdd('day', 7, col)` fails).
+   */
+  private static readonly DATE_FUNCTIONS_WITH_INTERVAL_UNIT = new Set([
+    "dateadd",
+    "datesub",
+    "datediff",
+    "datetrunc",
+    "date_add",
+    "date_sub",
+    "date_diff",
+    "date_trunc",
+  ]);
+
+  /**
+   * Visit function call arguments, handling date functions that require an interval unit
+   * keyword as their first argument. For these functions, the first arg is output as a
+   * bare keyword instead of being parameterized or resolved as a column reference.
+   */
+  private visitCallArgs(functionName: string, args: Expression[]): string[] {
+    const lowerName = functionName.toLowerCase();
+
+    if (
+      ClickHousePrinter.DATE_FUNCTIONS_WITH_INTERVAL_UNIT.has(lowerName) &&
+      args.length > 0
+    ) {
+      const firstArg = args[0];
+      const intervalUnit = this.extractIntervalUnit(firstArg);
+
+      if (intervalUnit) {
+        return [intervalUnit, ...args.slice(1).map((arg) => this.visit(arg))];
+      }
+    }
+
+    return args.map((arg) => this.visit(arg));
+  }
+
+  /**
+   * Try to extract a valid interval unit keyword from an expression.
+   * Handles both string constants ('day') and bare identifiers (day).
+   * Returns the bare keyword string if valid, or null if not an interval unit.
+   */
+  private extractIntervalUnit(expr: Expression): string | null {
+    if (expr.expression_type === "constant") {
+      const value = (expr as Constant).value;
+      if (typeof value === "string" && ClickHousePrinter.INTERVAL_UNITS.has(value.toLowerCase())) {
+        return value.toLowerCase();
+      }
+    }
+
+    if (expr.expression_type === "field") {
+      const chain = (expr as Field).chain;
+      if (chain.length === 1 && typeof chain[0] === "string") {
+        const name = chain[0].toLowerCase();
+        if (ClickHousePrinter.INTERVAL_UNITS.has(name)) {
+          return name;
+        }
+      }
+    }
+
+    return null;
+  }
+
   private visitJoinConstraint(node: JoinConstraint): string {
     return this.visit(node.expr);
   }