Merge pull request #271 from kdhrubo/feature/270_revamp_query_engine

Feature/270 revamp query engine

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

@@ -2,18 +2,12 @@
 
 import com.homihq.db2rest.rest.read.dto.JoinDetail;
 import com.homihq.db2rest.rest.read.dto.ReadContextV2;
-import jakarta.servlet.http.HttpServletRequest;
 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.web.bind.annotation.*;
 
 import java.util.List;
 
-
 @RestController
 @Slf4j
 @RequiredArgsConstructor
@@ -23,28 +17,26 @@ public class ReadController {
 
     @GetMapping(value = "/{tableName}" , produces = "application/json")
     public Object findAll(@PathVariable String tableName,
-                                  @RequestHeader(name = "Accept-Profile", required = false) String schemaName,
-                                  @RequestParam(name = "select", required = false, defaultValue = "") String select,
-                                  @RequestParam(name = "filter", required = false, defaultValue = "") String filter,
-                                  Sort sort,
-                                  Pageable pageable, HttpServletRequest httpServletRequest) {
-
-        log.info("schemaName - {}", schemaName);
-        log.info("select - {}", select);
-        log.info("filter - {}", filter);
-        log.info("pageable - {}", pageable);
-
+                          @RequestParam(name = "fields", required = false, defaultValue = "*") String fields,
+                          @RequestParam(name = "filter", required = false, defaultValue = "") String filter,
+                          @RequestParam(name = "sort", required = false, defaultValue = "") List<String> sorts,
+                          @RequestParam(name = "limit", required = false, defaultValue = "-1") int limit,
+                          @RequestParam(name = "offset", required = false, defaultValue = "-1") long offset) {
 
-        if( getIntParameter(httpServletRequest, "page", -1) == -1 &&
-                getIntParameter(httpServletRequest, "size", -1) == -1) {
-            pageable = Pageable.unpaged(sort);
-        }
+        ReadContextV2 readContextV2 = ReadContextV2.builder()
+                .tableName(tableName)
+                .fields(fields)
+                .filter(filter)
+                .sorts(sorts)
+                .limit(limit)
+                .offset(offset)
+                .build();
 
 
-        return readService.findAll(schemaName, tableName,select, filter, pageable, sort);
+        return readService.findAll(readContextV2);
     }
 
-    @PostMapping(value = "/V2/{tableName}" , produces = "application/json")
+    @PostMapping(value = "/{tableName}/_expand" , produces = "application/json")
     public Object find(@PathVariable String tableName,
                        @RequestParam(name = "fields", required = false, defaultValue = "*") String fields,
                        @RequestParam(name = "filter", required = false, defaultValue = "") String filter,
@@ -54,14 +46,6 @@ public Object find(@PathVariable String tableName,
                        @RequestBody List<JoinDetail> joins
     ) {
 
-        log.info("fields - {}", fields);
-        log.info("filter - {}", filter);
-        log.info("sort - {}", sorts);
-        log.info("limit - {}", limit);
-        log.info("offset - {}", offset);
-
-        log.info("join - {}", joins);
-
         ReadContextV2 readContextV2 = ReadContextV2.builder()
                 .tableName(tableName)
                 .fields(fields)

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

@@ -1,71 +1,42 @@
 package com.homihq.db2rest.rest.read;
 
-import com.homihq.db2rest.rest.read.helper.*;
 import com.homihq.db2rest.rest.read.dto.ReadContextV2;
 import com.homihq.db2rest.rest.read.processor.QueryCreatorTemplate;
-import com.homihq.db2rest.rest.read.processor.pre.ReadPreProcessor;
+import com.homihq.db2rest.rest.read.processor.ReadProcessor;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.data.domain.Pageable;
-import org.springframework.data.domain.Sort;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
-import java.util.Map;
-
 
 
 @Service
 @Slf4j
 @RequiredArgsConstructor
 public class ReadService {
 
-    private final SelectBuilder selectBuilder;
-    private final JoinBuilder joinBuilder;
-    private final WhereBuilder whereBuilder;
-    private final LimitPaginationBuilder limitPaginationBuilder;
-    private final SortBuilder sortBuilder;
-
     private final NamedParameterJdbcTemplate namedParameterJdbcTemplate;
 
-    private final List<ReadPreProcessor> processorList;
+    private final List<ReadProcessor> processorList;
     private final QueryCreatorTemplate queryCreatorTemplate;
 
-    public Object findAll(String schemaName, String tableName, String select, String filter,
-                                     Pageable pageable, Sort sort) {
-        ReadContext ctx = ReadContext.builder()
-                .pageable(pageable).sort(sort)
-                .schemaName(schemaName)
-                .tableName(tableName).select(select).filter(filter).build();
-
-        selectBuilder.build(ctx);
-        //joinBuilder.build(ctx);
-        whereBuilder.build(ctx);
-        limitPaginationBuilder.build(ctx);
-        sortBuilder.build(ctx);
-
-        String sql = ctx.prepareSQL();
-        Map<String,Object> bindValues = ctx.prepareParameters();
-
-        log.info("SQL - {}", sql);
-        log.info("Bind variables - {}", bindValues);
-
-        return namedParameterJdbcTemplate.queryForList(sql, bindValues);
-
-    }
 
     public Object findAll(ReadContextV2 readContextV2) {
         try {
-            for (ReadPreProcessor processor : processorList) {
+            for (ReadProcessor processor : processorList) {
                 processor.process(readContextV2);
             }
-            log.info("** TIME TO GENERATE QUERY **");
-            queryCreatorTemplate.createQuery(readContextV2);
+
+            String sql = queryCreatorTemplate.createQuery(readContextV2);
+            log.info("{}", sql);
+            log.info("{}", readContextV2.getParamMap());
+            return namedParameterJdbcTemplate.queryForList(sql, readContextV2.getParamMap());
         }
         catch (Exception e) {
             e.printStackTrace();
         }
+
         return null;
     }
 

src/main/java/com/homihq/db2rest/rest/read/dto/JoinDetail.java

@@ -1,18 +1,24 @@
 package com.homihq.db2rest.rest.read.dto;
 
 import org.apache.commons.lang3.StringUtils;
-import org.mybatis.dynamic.sql.select.join.JoinType;
 
 import java.util.List;
+import java.util.Objects;
 
 
-public record JoinDetail (String table, List<String> fields,String on, List<String> andFilters, String type){
+public record JoinDetail (String table, String with, List<String> fields,
+                          List<String> on, String filter, String type){
 
-    public JoinType getJoinType() {
-        return StringUtils.isBlank(type) ? JoinType.INNER :
-                JoinType.valueOf(StringUtils.upperCase(type));
+    public String getJoinType() {
+        return StringUtils.isBlank(type) ? "INNER" :
+                StringUtils.upperCase(type);
 
     }
+    public boolean hasOn() {
+        return Objects.nonNull(on) && !on.isEmpty();
+    }
 
-
+    public boolean hasFilter() {
+        return StringUtils.isNotBlank(filter);
+    }
 }

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

@@ -3,6 +3,7 @@
 import jakarta.validation.constraints.NotEmpty;
 import java.util.Map;
 
+@Deprecated
 public record QueryRequest(@NotEmpty(message = "Sql statement cannot be empty") String sql, Map<String, Object> params,
                            boolean single) {
 }

src/main/java/com/homihq/db2rest/rest/read/dto/ReadContextV2.java

@@ -1,19 +1,17 @@
 package com.homihq.db2rest.rest.read.dto;
 
-import com.homihq.db2rest.mybatis.MyBatisTable;
-import com.homihq.db2rest.rest.read.dto.JoinDetail;
+
 import com.homihq.db2rest.rest.read.model.DbColumn;
+import com.homihq.db2rest.rest.read.model.DbJoin;
 import com.homihq.db2rest.rest.read.model.DbTable;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.mybatis.dynamic.sql.BasicColumn;
-import org.mybatis.dynamic.sql.SqlCriterion;
 
-import java.util.List;
-import java.util.Map;
+
+import java.util.*;
 
 @Builder
 @AllArgsConstructor
@@ -32,25 +30,30 @@ public class ReadContextV2 {
     List<JoinDetail> joins;
 
 
-    /* Processed attributes */
-    MyBatisTable rootTable;
-    List<BasicColumn> columns;
-    SqlCriterion whereCondition;
-
-
     /* Attributes to replace the ones above */
     DbTable root;
     List<DbColumn> cols;
     String rootWhere;
     Map<String,Object> paramMap;
-
-    public void addWhereCondition(SqlCriterion whereCondition) {
-        this.whereCondition = whereCondition;
+    List<DbJoin> dbJoins;
+
+    public boolean createParamMap() {
+        if(Objects.isNull(paramMap)) {
+            paramMap = new HashMap<>();
+            return true;
+        }
+        else{
+            return false;
+        }
     }
 
+    public void addColumns(List<DbColumn> columnList) {
+        this.cols.addAll(columnList);
+    }
 
+    public void addJoin(DbJoin join) {
+        if(Objects.isNull(dbJoins)) dbJoins = new ArrayList<>();
 
-    public void addColumns(List<BasicColumn> columnList) {
-        this.columns.addAll(columnList);
+        dbJoins.add(join);
     }
 }

src/main/java/com/homihq/db2rest/rest/read/helper/AliasGenerator.java

@@ -0,0 +1,18 @@
+package com.homihq.db2rest.rest.read.helper;
+
+
+import org.springframework.stereotype.Component;
+
+import java.util.Random;
+
+@Component
+public class AliasGenerator {
+    private Random random = new Random();
+    public String getAlias(String prefix, int length, String sqlIdentifier) {
+        return
+        sqlIdentifier.length() > length ?
+                prefix + sqlIdentifier.substring(0,length) + "_" +random.nextInt(2000)
+            :  prefix + sqlIdentifier + "_" +random.nextInt(2000);
+
+    }
+}

src/main/java/com/homihq/db2rest/rest/read/helper/JoinBuilder.java

@@ -22,6 +22,7 @@
 @Component
 @Slf4j
 @RequiredArgsConstructor
+@Deprecated
 public class JoinBuilder  {
 
     private final SchemaManager schemaManager;

src/main/java/com/homihq/db2rest/rest/read/helper/LimitPaginationBuilder.java

@@ -9,6 +9,7 @@
 @Component
 @Slf4j
 @RequiredArgsConstructor
+@Deprecated
 public class LimitPaginationBuilder {
 
     public void build(ReadContext context) {

src/main/java/com/homihq/db2rest/rest/read/helper/ReadContext.java

@@ -32,6 +32,7 @@
 @NoArgsConstructor
 @Data
 @Slf4j
+@Deprecated
 public class ReadContext {
 
     String schemaName;

src/main/java/com/homihq/db2rest/rest/read/helper/SelectBuilder.java

@@ -14,6 +14,7 @@
 @Component
 @Slf4j
 @RequiredArgsConstructor
+@Deprecated
 public class SelectBuilder{
 
     private final SchemaManager schemaManager;

src/main/java/com/homihq/db2rest/rest/read/helper/SortBuilder.java

@@ -15,6 +15,7 @@
 @Component
 @Slf4j
 @RequiredArgsConstructor
+@Deprecated
 public class SortBuilder {
 
     public void build(ReadContext context) {

src/main/java/com/homihq/db2rest/rest/read/helper/TableUtil.java

@@ -8,6 +8,8 @@ public abstract class TableUtil {
 
     private TableUtil() {}
 
+
+
     public static DbTable getTable(String tableName) {
         //check if table contains schema name
 

src/main/java/com/homihq/db2rest/rest/read/helper/WhereBuilder.java

@@ -14,6 +14,7 @@
 @Component
 @RequiredArgsConstructor
 @Slf4j
+@Deprecated
 public class WhereBuilder{
 
 

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

@@ -5,7 +5,13 @@
 
 import java.sql.JDBCType;
 
-public record DbColumn(String tableName, String name, JDBCType jdbcType, Column column, String alias) {
+public record DbColumn(String tableName, String name, JDBCType jdbcType, Column column, String alias, String tableAlias) {
 
+    public String render() {
+        return tableAlias + "."+ name + " " + alias;
+    }
 
+    public String getAliasedName() {return tableAlias + "."+ name;}
+
+    public String getAliasedNameParam() {return tableAlias + "_"+ name;}
 }