Adding filterIf and filterOpt utility methods to Select

docs/reference.md

@@ -738,6 +738,130 @@ ShippingInfo.select
 
 
 
+### Select.filterIf.filter not added
+
+
+
+```scala
+ShippingInfo.select.filterIf(false)(_.buyerId `=` 2)
+```
+
+
+*
+    ```sql
+    SELECT
+        shipping_info0.id AS id,
+        shipping_info0.buyer_id AS buyer_id,
+        shipping_info0.shipping_date AS shipping_date
+      FROM shipping_info shipping_info0
+    ```
+
+
+
+*
+    ```scala
+    Seq(
+      ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+      ShippingInfo[Sc](2, 1, LocalDate.parse("2012-04-05")),
+      ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+    )
+    ```
+
+
+
+### Select.filterIf.filter added
+
+
+
+```scala
+ShippingInfo.select.filterIf(true)(_.buyerId `=` 2)
+```
+
+
+*
+    ```sql
+    SELECT
+        shipping_info0.id AS id,
+        shipping_info0.buyer_id AS buyer_id,
+        shipping_info0.shipping_date AS shipping_date
+      FROM shipping_info shipping_info0
+      WHERE (shipping_info0.buyer_id = ?)
+    ```
+
+
+
+*
+    ```scala
+    Seq(
+      ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+      ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+    )
+    ```
+
+
+
+### Select.filterOpt.filter not added
+
+
+
+```scala
+ShippingInfo.select.filterOpt[Int](None)((table, value) => table.buyerId `=` value)
+```
+
+
+*
+    ```sql
+    SELECT
+        shipping_info0.id AS id,
+        shipping_info0.buyer_id AS buyer_id,
+        shipping_info0.shipping_date AS shipping_date
+      FROM shipping_info shipping_info0
+    ```
+
+
+
+*
+    ```scala
+    Seq(
+      ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+      ShippingInfo[Sc](2, 1, LocalDate.parse("2012-04-05")),
+      ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+    )
+    ```
+
+
+
+### Select.filterOpt.filter added
+
+
+
+```scala
+ShippingInfo.select.filterOpt(Some(2))((table, value) => table.buyerId `=` value)
+```
+
+
+*
+    ```sql
+    SELECT
+        shipping_info0.id AS id,
+        shipping_info0.buyer_id AS buyer_id,
+        shipping_info0.shipping_date AS shipping_date
+      FROM shipping_info shipping_info0
+      WHERE (shipping_info0.buyer_id = ?)
+    ```
+
+
+
+*
+    ```scala
+    Seq(
+      ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+      ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+    )
+    ```
+
+
+
 ### Select.map.single
 
 `.map` allows you to select exactly what you want to return from

scalasql/query/src/Select.scala

@@ -101,6 +101,21 @@ trait Select[Q, R]
    */
   def withFilter(f: Q => Expr[Boolean]): Select[Q, R] = filter(f)
 
+  /**
+   * Filters this [[Select]] with the given predicate, if [[cond]] evaluates to true
+   */
+  def filterIf(cond: Boolean)(
+      f: Q => Expr[Boolean]
+  ): Select[Q, R]
+
+  /**
+   * Filters this [[Select]] with the given predicate consuming provided option as a part of predicate's input,
+   * if this option is Some[T]
+   */
+  def filterOpt[T](option: Option[T])(
+      f: (Q, T) => Expr[Boolean]
+  ): Select[Q, R]
+
   /**
    * Performs one or more aggregates in a single [[Select]]
    */
@@ -214,6 +229,9 @@ trait Select[Q, R]
    */
   def head: Query.Single[R] = take(1).single
 
+  // TODO
+  // def headOption: Query.Single[Option[R]] = take(1).single
+
   /**
    * Converts this [[Select]] into an [[Expr]], assuming it returns a single row and
    * a single column. Note that if this returns multiple rows, behavior is database-specific,
@@ -325,6 +343,12 @@ object Select {
 
     override def filter(f: Q => Expr[Boolean]): Select[Q, R] = selectToSimpleSelect().filter(f)
 
+    override def filterIf(cond: Boolean)(f: Q => Expr[Boolean]): Select[Q, R] =
+      selectToSimpleSelect().filterIf(cond)(f)
+
+    override def filterOpt[T](option: Option[T])(f: (Q, T) => Expr[Boolean]): Select[Q, R] =
+      selectToSimpleSelect().filterOpt(option)(f)
+
     override def aggregate[E, V](f: Aggregatable.Proxy[Q] => E)(
         implicit qr: Queryable.Row[E, V]
     ): Aggregate[E, V] = selectToSimpleSelect().aggregate(f)

scalasql/query/src/SimpleSelect.scala

@@ -95,6 +95,14 @@ class SimpleSelect[Q, R](
     else copy(groupBy0 = groupBy0.map(g => g.copy(having = g.having ++ Seq(f(expr)))))
   }
 
+  def filterIf(cond: Boolean)(f: Q => Expr[Boolean]): Select[Q, R] =
+    if (cond) this.filter(f) else this
+
+  def filterOpt[T](option: Option[T])(f: (Q, T) => Expr[Boolean]): Select[Q, R] = option match {
+    case None => this
+    case Some(opt) => this.filter(q => f(q, opt))
+  }
+
   def join0[Q2, R2, QF, RF](
       prefix: String,
       other: Joinable[Q2, R2],

scalasql/test/src/query/SelectTests.scala

@@ -141,6 +141,80 @@ trait SelectTests extends ScalaSqlSuite {
       )
     }
 
+    test("filterIf") {
+      test("filter not added") - checker(
+        query = Text { ShippingInfo.select.filterIf(false)(_.buyerId `=` 2) },
+        sql = """
+          SELECT
+              shipping_info0.id AS id,
+              shipping_info0.buyer_id AS buyer_id,
+              shipping_info0.shipping_date AS shipping_date
+            FROM shipping_info shipping_info0
+        """,
+        value = Seq(
+          ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+          ShippingInfo[Sc](2, 1, LocalDate.parse("2012-04-05")),
+          ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+        ),
+        docs = ""
+      )
+      test("filter added") - checker(
+        query = Text { ShippingInfo.select.filterIf(true)(_.buyerId `=` 2) },
+        sql = """
+          SELECT
+              shipping_info0.id AS id,
+              shipping_info0.buyer_id AS buyer_id,
+              shipping_info0.shipping_date AS shipping_date
+            FROM shipping_info shipping_info0
+            WHERE (shipping_info0.buyer_id = ?)
+        """,
+        value = Seq(
+          ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+          ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+        ),
+        docs = ""
+      )
+    }
+
+    test("filterOpt") {
+      test("filter not added") - checker(
+        query = Text {
+          ShippingInfo.select.filterOpt[Int](None)((table, value) => table.buyerId `=` value)
+        },
+        sql = """
+          SELECT
+              shipping_info0.id AS id,
+              shipping_info0.buyer_id AS buyer_id,
+              shipping_info0.shipping_date AS shipping_date
+            FROM shipping_info shipping_info0
+        """,
+        value = Seq(
+          ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+          ShippingInfo[Sc](2, 1, LocalDate.parse("2012-04-05")),
+          ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+        ),
+        docs = ""
+      )
+      test("filter added") - checker(
+        query = Text {
+          ShippingInfo.select.filterOpt(Some(2))((table, value) => table.buyerId `=` value)
+        },
+        sql = """
+          SELECT
+              shipping_info0.id AS id,
+              shipping_info0.buyer_id AS buyer_id,
+              shipping_info0.shipping_date AS shipping_date
+            FROM shipping_info shipping_info0
+            WHERE (shipping_info0.buyer_id = ?)
+        """,
+        value = Seq(
+          ShippingInfo[Sc](1, 2, LocalDate.parse("2010-02-03")),
+          ShippingInfo[Sc](3, 2, LocalDate.parse("2012-05-06"))
+        ),
+        docs = ""
+      )
+    }
+
     test("map") {
       test("single") - checker(
         query = Text { Buyer.select.map(_.name) },