Added support for where

docs/README.md

@@ -18,6 +18,7 @@ Welcome to the sqlgen documentation. This guide provides detailed information ab
 - [sqlgen::update](update.md) - How to update data in a table
 - [sqlgen::delete_from](delete_from.md) - How to delete data from a table
 - [sqlgen::drop](drop.md) - How to drop a table
+- [sqlgen::create_index](create_index.md) - How to create an index on a table
 - [Transactions](transactions.md) - How to use transactions for atomic operations
 
 ## Data Types and Validation

include/sqlgen/where.hpp

@@ -4,6 +4,7 @@
 #include <type_traits>
 
 #include "Result.hpp"
+#include "create_index.hpp"
 #include "delete_from.hpp"
 #include "read.hpp"
 #include "transpilation/Limit.hpp"
@@ -17,6 +18,19 @@ struct Where {
   ConditionType condition;
 };
 
+template <rfl::internal::StringLiteral _name, class ValueType, class WhereType,
+          class... ColTypes, class ConditionType>
+auto operator|(const CreateIndex<_name, ValueType, WhereType, ColTypes...>& _c,
+               const Where<ConditionType>& _where) {
+  static_assert(std::is_same_v<WhereType, Nothing>,
+                "You cannot call where(...) twice (but you can apply more "
+                "than one condition by combining them with && or ||).");
+  return CreateIndex<_name, ValueType, ConditionType, ColTypes...>{
+      .unique_ = _c.unique_,
+      .if_not_exists_ = _c.if_not_exists_,
+      .where_ = _where.condition};
+}
+
 template <class ValueType, class WhereType, class ConditionType>
 auto operator|(const DeleteFrom<ValueType, WhereType>& _d,
                const Where<ConditionType>& _where) {

tests/postgres/test_create_index_where.cpp

@@ -0,0 +1,45 @@
+#ifndef SQLGEN_BUILD_DRY_TESTS_ONLY
+
+#include <gtest/gtest.h>
+
+#include <rfl.hpp>
+#include <rfl/json.hpp>
+#include <sqlgen.hpp>
+#include <sqlgen/postgres.hpp>
+#include <vector>
+
+namespace test_create_index_where {
+
+struct Person {
+  sqlgen::PrimaryKey<uint32_t> id;
+  std::string first_name;
+  std::string last_name;
+  int age;
+};
+
+TEST(postgres, test_create_index_where) {
+  const auto credentials = sqlgen::postgres::Credentials{.user = "postgres",
+                                                         .password = "password",
+                                                         .host = "localhost",
+                                                         .dbname = "postgres"};
+
+  using namespace sqlgen;
+
+  const auto people =
+      sqlgen::postgres::connect(credentials)
+          .and_then(drop<Person> | if_exists)
+          .and_then(create_table<Person> | if_not_exists)
+          .and_then(create_index<"test_table_ix", Person>(
+                        "first_name"_c, "last_name"_c, "age"_c) |
+                    if_not_exists | where("age"_c > 0))
+          .and_then(sqlgen::read<std::vector<Person>>)
+          .value();
+
+  const std::string expected = R"([])";
+
+  EXPECT_EQ(rfl::json::write(people), expected);
+}
+
+}  // namespace test_create_index_where
+
+#endif

tests/postgres/test_create_index_where_dry.cpp

@@ -0,0 +1,27 @@
+#include <gtest/gtest.h>
+
+#include <sqlgen.hpp>
+#include <sqlgen/postgres.hpp>
+
+namespace test_create_index_where_dry {
+
+struct TestTable {
+  std::string field1;
+  int32_t field2;
+  sqlgen::PrimaryKey<uint32_t> id;
+  std::optional<std::string> nullable;
+};
+
+TEST(postgres, test_create_index_where_dry) {
+  using namespace sqlgen;
+
+  const auto query =
+      create_index<"test_table_ix", TestTable>("field1"_c, "field2"_c) |
+      if_not_exists | where("field2"_c > 0);
+
+  const auto expected =
+      R"(CREATE INDEX IF NOT EXISTS "test_table_ix" ON "TestTable"("field1", "field2") WHERE "field2" > 0;)";
+
+  EXPECT_EQ(sqlgen::postgres::to_sql(query), expected);
+}
+}  // namespace test_create_index_where_dry