Api to execute custom query

pom.xml

@@ -114,6 +114,10 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-webflux</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
 
         <dependency>
             <groupId>com.ibm.db2</groupId>

src/main/java/com/homihq/db2rest/exception/GlobalExceptionHandler.java

@@ -1,9 +1,40 @@
 package com.homihq.db2rest.exception;
 
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatusCode;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.context.request.WebRequest;
 import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
 
+import java.time.Instant;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+
 @RestControllerAdvice
 public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
 
+    @Override
+    protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex,
+                                                                  HttpHeaders headers,
+                                                                  HttpStatusCode status, WebRequest request) {
+        var body = new LinkedHashMap<>();
+        body.put("type", "https://github.com/kdhrubo/db2rest/invalid-arguments");
+        body.put("title", "Invalid arguments in the request");
+        body.put("status", status.value());
+        var errors = ex.getBindingResult()
+                .getFieldErrors()
+                .stream()
+                .map(error -> Map.of(error.getField(), Objects.requireNonNull(error.getDefaultMessage())))
+                .toList();
+        body.put("detail", errors);
+        body.put("instance", ((ServletWebRequest) request).getRequest().getRequestURI());
+        body.put("errorCategory", "Invalid-Arguments");
+        body.put("timestamp", Instant.now());
+        return new ResponseEntity<>(body, headers, status);
+    }
+
 }

src/main/java/com/homihq/db2rest/rest/read/ReadController.java

@@ -1,12 +1,17 @@
 package com.homihq.db2rest.rest.read;
 
+import com.homihq.db2rest.rest.read.model.QueryRequest;
 import jakarta.servlet.http.HttpServletRequest;
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 
 import static org.springframework.web.bind.ServletRequestUtils.*;
+
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
 
@@ -39,7 +44,11 @@ public Object findByJoinTable(@PathVariable String tableName,
 
         return readService.findAll(schemaName, tableName,select, filter, pageable, sort);
     }
-
-
+    @PostMapping(value = "/query", consumes = MediaType.APPLICATION_JSON_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<Object> findByCustomQuery(@RequestBody @Valid QueryRequest queryRequest) {
+        log.debug("Execute SQL statement {} with params {}", queryRequest.getSql(), queryRequest.getParams());
+        return ResponseEntity.ok(readService.findByCustomQuery(queryRequest));
+    }
 
 }

src/main/java/com/homihq/db2rest/rest/read/ReadService.java

@@ -1,6 +1,7 @@
 package com.homihq.db2rest.rest.read;
 
 import com.homihq.db2rest.rest.read.helper.*;
+import com.homihq.db2rest.rest.read.model.QueryRequest;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.data.domain.Pageable;
@@ -46,8 +47,9 @@ public Object findAll(String schemaName, String tableName, String select, String
 
     }
 
-
-
-
-
+    Object findByCustomQuery(QueryRequest queryRequest) {
+        return queryRequest.isSingle() ?
+                namedParameterJdbcTemplate.queryForMap(queryRequest.getSql(), queryRequest.getParams()) :
+                namedParameterJdbcTemplate.queryForList(queryRequest.getSql(), queryRequest.getParams());
+    }
 }

src/main/java/com/homihq/db2rest/rest/read/model/QueryRequest.java

@@ -0,0 +1,19 @@
+package com.homihq.db2rest.rest.read.model;
+
+import jakarta.validation.constraints.NotEmpty;
+import lombok.Builder;
+import lombok.Data;
+
+import java.util.Map;
+
+@Data
+@Builder
+public class QueryRequest {
+
+    @NotEmpty(message = "Sql statement cannot be empty")
+    private String sql;
+
+    private Map<String, Object> params;
+
+    private boolean isSingle;
+}

src/test/java/com/homihq/db2rest/rest/PgReadControllerTest.java

@@ -1,20 +1,18 @@
 package com.homihq.db2rest.rest;
 
 import com.homihq.db2rest.PostgreSQLBaseIntegrationTest;
-
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.http.MediaType;
-import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.*;
-
-import static org.springframework.restdocs.headers.HeaderDocumentation.headerWithName;
-import static org.springframework.restdocs.headers.HeaderDocumentation.responseHeaders;
-import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.*;
-import static org.springframework.restdocs.mockmvc.RestDocumentationRequestBuilders.*;
-import static org.springframework.restdocs.operation.preprocess.Preprocessors.*;
-import static org.springframework.restdocs.payload.PayloadDocumentation.*;
-import static org.springframework.restdocs.request.RequestDocumentation.*;
+
+import static org.hamcrest.Matchers.*;
+import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.document;
+import static org.springframework.restdocs.mockmvc.RestDocumentationRequestBuilders.get;
+import static org.springframework.restdocs.mockmvc.RestDocumentationRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
 class PgReadControllerTest extends PostgreSQLBaseIntegrationTest {
 
     @Test
@@ -27,4 +25,70 @@ void findAllFilms() throws Exception {
                 .andDo(print())
                 .andDo(document("pg-get-all-films"));
     }
+
+    @Test
+    @DisplayName("Query returns single result")
+    void query_returns_single_result() throws Exception {
+        var json = """ 
+                       {
+                             "sql": "SELECT FIRST_NAME,LAST_NAME FROM ACTOR WHERE ACTOR_ID = :id",
+                             "params" : {
+                                 "id" : 1
+                             },
+                             "single" : true
+                         }
+                """;
+
+        mockMvc.perform(post("/query").contentType(MediaType.APPLICATION_JSON).characterEncoding("utf-8")
+                        .content(json).accept(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.first_name", equalTo("PENELOPE")))
+                .andDo(print())
+                .andDo(document("pg-create-a-film"));
+    }
+
+    @Test
+    @DisplayName("Query returns list of results")
+    void query_returns_list_of_results() throws Exception {
+        var json = """ 
+                       {
+                           "sql": "SELECT FIRST_NAME,LAST_NAME FROM ACTOR WHERE ACTOR_ID IN (:id1, :id2)",
+                           "params" : {
+                               "id1" : 1,
+                               "id2" : 2
+                           },
+                           "single" : false
+                       }
+                """;
+
+        mockMvc.perform(post("/query").contentType(MediaType.APPLICATION_JSON).characterEncoding("utf-8")
+                        .content(json).accept(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.*", hasSize(2)))
+                .andExpect(jsonPath("$[0].first_name", equalTo("PENELOPE")))
+                .andExpect(jsonPath("$[1].last_name", equalTo("WAHLBERG")))
+                .andDo(print())
+                .andDo(document("pg-create-a-film"));
+    }
+
+    @Test
+    @DisplayName("Query returns 400 bad request error")
+    void query_returns_400_bad_request() throws Exception {
+        var json = """ 
+                       {
+                           "sql": "",
+                           "params" : {
+                               "id1" : 1
+                           },
+                           "single" : false
+                       }
+                """;
+
+        mockMvc.perform(post("/query").contentType(MediaType.APPLICATION_JSON).characterEncoding("utf-8")
+                        .content(json).accept(MediaType.APPLICATION_JSON))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.status", is(400)))
+                .andDo(print())
+                .andDo(document("pg-create-a-film"));
+    }
 }