added sql builder framework

src/test/kotlin/dev/mduchene/sql/SqlBuilderTest.kt

@@ -0,0 +1,135 @@
+package dev.mduchene.sql
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+class SqlBuilderTest {
+  @Test
+  fun `builds select with joins count grouping and paging`() {
+    val statement = Sql
+      .select(
+        Sql.col("u.id"),
+        Sql.col("u.email"),
+        Sql.count(Sql.col("p.id")).asAlias("post_count"),
+      )
+      .from("users", "u")
+      .leftJoin("posts", "p", Sql.col("p.user_id").eq(Sql.col("u.id")))
+      .where(Sql.col("u.status").eq("active"))
+      .andWhere(Sql.col("u.deleted_at").isNull())
+      .groupBy("u.id", "u.email")
+      .having(Sql.count(Sql.col("p.id")).gt(0))
+      .orderBy(Sql.col("u.created_at").desc(NullsOrder.LAST))
+      .limit(25)
+      .offset(50)
+      .toSql()
+
+    assertEquals(
+      """SELECT "u"."id", "u"."email", COUNT("p"."id") AS "post_count" FROM "users" AS "u" LEFT JOIN "posts" AS "p" ON ("p"."user_id" = "u"."id") WHERE (("u"."status" = $1) AND ("u"."deleted_at" IS NULL)) GROUP BY "u"."id", "u"."email" HAVING (COUNT("p"."id") > $2) ORDER BY "u"."created_at" DESC NULLS LAST LIMIT 25 OFFSET 50""",
+      statement.sql,
+    )
+    assertEquals(listOf("active", 0), statement.parameters)
+  }
+
+  @Test
+  fun `builds insert with multiple rows and returning`() {
+    val statement = Sql
+      .insertInto("users")
+      .columns("email", "display_name")
+      .values("sakura@example.com", "Sakura")
+      .values("naruto@example.com", "Naruto")
+      .returning("id")
+      .toSql()
+
+    assertEquals(
+      """INSERT INTO "users" ("email", "display_name") VALUES ($1, $2), ($3, $4) RETURNING "id"""",
+      statement.sql,
+    )
+    assertEquals(
+      listOf("sakura@example.com", "Sakura", "naruto@example.com", "Naruto"),
+      statement.parameters,
+    )
+  }
+
+  @Test
+  fun `builds update with raw expression and where clause`() {
+    val statement = Sql
+      .update("users")
+      .set("display_name", "Hinata")
+      .set("updated_at", Sql.raw("CURRENT_TIMESTAMP"))
+      .where(Sql.col("id").eq(42))
+      .returning("id", "updated_at")
+      .toSql()
+
+    assertEquals(
+      """UPDATE "users" SET "display_name" = $1, "updated_at" = CURRENT_TIMESTAMP WHERE ("id" = $2) RETURNING "id", "updated_at"""",
+      statement.sql,
+    )
+    assertEquals(listOf("Hinata", 42), statement.parameters)
+  }
+
+  @Test
+  fun `builds delete with cte and subquery`() {
+    val inactiveUsers = Sql
+      .select("id")
+      .from("users")
+      .where(Sql.col("last_seen_at").lt(Sql.raw("CURRENT_DATE - INTERVAL '1 year'")))
+
+    val statement = Sql
+      .deleteFrom("sessions")
+      .with("inactive_users", inactiveUsers)
+      .where(
+        Sql.col("user_id").inSubquery(
+          Sql.select("id").from("inactive_users"),
+        ),
+      )
+      .toSql()
+
+    assertEquals(
+      """WITH "inactive_users" AS (SELECT "id" FROM "users" WHERE ("last_seen_at" < CURRENT_DATE - INTERVAL '1 year')) DELETE FROM "sessions" WHERE ("user_id" IN (SELECT "id" FROM "inactive_users"))""",
+      statement.sql,
+    )
+    assertEquals(emptyList(), statement.parameters)
+  }
+
+  @Test
+  fun `can render ansi placeholders from the same builder`() {
+    val builder = Sql
+      .select("id")
+      .from("users")
+      .where(Sql.col("email").eq("sakura@example.com"))
+      .andWhere(Sql.col("status").eq("active"))
+
+    assertEquals(
+      """SELECT "id" FROM "users" WHERE (("email" = $1) AND ("status" = $2))""",
+      builder.toSql(PostgresDialect).sql,
+    )
+
+    val ansi = builder.toSql(AnsiDialect)
+    assertEquals(
+      """SELECT "id" FROM "users" WHERE (("email" = ?) AND ("status" = ?))""",
+      ansi.sql,
+    )
+    assertEquals(listOf("sakura@example.com", "active"), ansi.parameters)
+  }
+
+  @Test
+  fun `rejects returning for dialects that do not support it`() {
+    val builder = Sql
+      .insertInto("users")
+      .columns("email")
+      .values("sakura@example.com")
+      .returning("id")
+
+    assertFailsWith<IllegalArgumentException> {
+      builder.toSql(AnsiDialect)
+    }
+  }
+
+  @Test
+  fun `rejects unsafe identifiers unless raw sql is explicit`() {
+    assertFailsWith<IllegalArgumentException> {
+      Sql.select("id; DROP TABLE users").from("users").toSql()
+    }
+  }
+}