添加子查询

mybatis-plus-join-core/src/main/java/com/github/yulichang/toolkit/WrapperUtils.java

@@ -0,0 +1,114 @@
+package com.github.yulichang.toolkit;
+
+import com.baomidou.mybatisplus.core.metadata.TableFieldInfo;
+import com.baomidou.mybatisplus.core.metadata.TableInfo;
+import com.baomidou.mybatisplus.core.toolkit.Constants;
+import com.baomidou.mybatisplus.core.toolkit.StringPool;
+import com.baomidou.mybatisplus.core.toolkit.StringUtils;
+import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
+import com.github.yulichang.adapter.AdapterHelper;
+import com.github.yulichang.toolkit.sql.SqlScriptUtils;
+import com.github.yulichang.wrapper.MPJLambdaWrapper;
+
+import java.util.Objects;
+import java.util.Optional;
+
+/**
+ * @author yulichang
+ * @since 1.4.5
+ */
+public class WrapperUtils {
+
+    public static <T, R> String buildSqlByWrapper(Class<T> clazz, MPJLambdaWrapper<T> wrapper, SFunction<R, ?> alias) {
+        TableInfo tableInfo = TableHelper.get(clazz);
+        Asserts.hasTable(tableInfo, clazz);
+        String first = Optional.ofNullable(wrapper.getSqlFirst()).orElse(StringPool.EMPTY);
+        boolean hasWhere = false;
+        String entityWhere = getEntitySql(tableInfo, wrapper);
+        if (StringUtils.isNotBlank(entityWhere)) {
+            hasWhere = true;
+        }
+        String mainLogic = mainLogic(hasWhere, clazz, wrapper);
+        if (StringUtils.isNotBlank(mainLogic)) {
+            hasWhere = true;
+        }
+        String subLogic = subLogic(hasWhere, wrapper);
+        if (StringUtils.isNotBlank(subLogic)) {
+            hasWhere = true;
+        }
+        String sqlSegment = (wrapper.getSqlSegment() != null && StringUtils.isNotBlank(wrapper.getSqlSegment())) ?
+                ((wrapper.isEmptyOfNormal() ? StringPool.EMPTY : (hasWhere ? " AND " : " WHERE ")) + wrapper.getSqlSegment()) : StringPool.EMPTY;
+
+        String sqlComment = Optional.ofNullable(wrapper.getSqlComment()).orElse(StringPool.EMPTY);
+        return String.format("(%s SELECT %s FROM %s %s %s %s %s %s %s) AS %s",
+                first,
+                wrapper.getSqlSelect(),
+                tableInfo.getTableName(),
+                wrapper.getAlias(),
+                wrapper.getFrom(),
+                mainLogic,
+                subLogic,
+                sqlSegment,
+                sqlComment,
+                LambdaUtils.getName(alias));
+    }
+
+    private static <T> String formatParam(MPJLambdaWrapper<T> wrapper, Object param) {
+        final String genParamName = Constants.WRAPPER_PARAM + wrapper.getParamNameSeq().incrementAndGet();
+        final String paramStr = wrapper.getParamAlias() + ".paramNameValuePairs." + genParamName;
+        wrapper.getParamNameValuePairs().put(genParamName, param);
+        return SqlScriptUtils.safeParam(paramStr, null);
+    }
+
+    private static <T> String getEntitySql(TableInfo tableInfo, MPJLambdaWrapper<T> wrapper) {
+        T obj = wrapper.getEntity();
+        if (Objects.isNull(obj)) {
+            return StringPool.EMPTY;
+        }
+        StringBuilder sb = new StringBuilder(StringPool.EMPTY);
+        for (TableFieldInfo fieldInfo : tableInfo.getFieldList()) {
+            if (AdapterHelper.getTableInfoAdapter().mpjHasLogic(tableInfo) && fieldInfo.isLogicDelete()) {
+                continue;
+            }
+            Object val;
+            try {
+                val = fieldInfo.getField().get(obj);
+            } catch (IllegalAccessException e) {
+                throw new RuntimeException(e);
+            }
+            if (Objects.isNull(val)) {
+                continue;
+            }
+            sb.append(" AND ").append(wrapper.getTableList().getPrefixByClass(obj.getClass())).append(Constants.DOT)
+                    .append(fieldInfo.getColumn()).append(Constants.EQUALS).append(formatParam(wrapper, val));
+        }
+        //条件不为空 加上 where
+        if (sb.length() > 0) {
+            sb.delete(0, 4);
+            sb.insert(0, " WHERE ");
+        }
+        return sb.toString();
+    }
+
+    private static <T> String mainLogic(boolean hasWhere, Class<T> clazz, MPJLambdaWrapper<T> wrapper) {
+        String info = LogicInfoUtils.getLogicInfo(null, clazz, true, wrapper.getAlias());
+        if (StringUtils.isNotBlank(info)) {
+            if (hasWhere) {
+                return " AND " + info;
+            }
+            return " WHERE " + info.substring(4);
+        }
+        return StringPool.EMPTY;
+    }
+
+    private static <T> String subLogic(boolean hasWhere, MPJLambdaWrapper<T> wrapper) {
+        String sql = wrapper.getSubLogicSql();
+        if (StringUtils.isNotBlank(sql)) {
+            if (hasWhere) {
+                return sql;
+            }
+            return " WHERE " + sql.substring(4);
+        }
+        return StringPool.EMPTY;
+    }
+}

mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJAbstractLambdaWrapper.java

@@ -43,6 +43,10 @@ public abstract class MPJAbstractLambdaWrapper<T, Children extends MPJAbstractLa
      * 主表别名
      */
     protected String alias = ConfigProperties.tableAlias;
+    /**
+     * 副表别名
+     */
+    protected String subTableAlias = ConfigProperties.tableAlias;
     /**
      * 是否构建是否存在一对多
      */
@@ -378,8 +382,8 @@ public abstract class MPJAbstractLambdaWrapper<T, Children extends MPJAbstractLa
         instance.isMain = false;
         onWrappers.add(instance);
         if (StringUtils.isBlank(tableAlias)) {
-            tableList.put(oldIndex, clazz, false, ConfigProperties.tableAlias, newIndex);
+            tableList.put(oldIndex, clazz, false, subTableAlias, newIndex);
-            instance.alias = ConfigProperties.tableAlias;
+            instance.alias = subTableAlias;
             instance.hasAlias = false;
         } else {
             tableList.put(oldIndex, clazz, true, tableAlias, newIndex);

mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJAbstractWrapper.java

@@ -51,6 +51,7 @@ public abstract class MPJAbstractWrapper<T, Children extends MPJAbstractWrapper<
     /**
      * 必要度量
      */
+    @Getter
     protected AtomicInteger paramNameSeq;
     protected Map<String, Object> paramNameValuePairs;
     /**
@@ -103,6 +104,7 @@ public abstract class MPJAbstractWrapper<T, Children extends MPJAbstractWrapper<
     /**
      * 关联的表
      */
+    @Getter
     protected TableList tableList;
 
     @Override

mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJLambdaWrapper.java

@@ -10,6 +10,7 @@ import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
 import com.github.yulichang.toolkit.Constant;
 import com.github.yulichang.toolkit.LambdaUtils;
 import com.github.yulichang.toolkit.TableList;
+import com.github.yulichang.toolkit.WrapperUtils;
 import com.github.yulichang.toolkit.support.ColumnCache;
 import com.github.yulichang.wrapper.interfaces.Chain;
 import com.github.yulichang.wrapper.interfaces.Query;
@@ -18,10 +19,12 @@ import com.github.yulichang.wrapper.resultmap.Label;
 import com.github.yulichang.wrapper.segments.Select;
 import com.github.yulichang.wrapper.segments.SelectCache;
 import com.github.yulichang.wrapper.segments.SelectNormal;
+import com.github.yulichang.wrapper.segments.SelectString;
 import lombok.Getter;
 
 import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 /**
@@ -174,6 +177,24 @@ public class MPJLambdaWrapper<T> extends MPJAbstractLambdaWrapper<T, MPJLambdaWr
         return typedThis;
     }
 
+    /**
+     * 子查询
+     */
+    public <E, F> MPJLambdaWrapper<T> selectSub(Class<E> clazz, Consumer<MPJLambdaWrapper<E>> consumer, SFunction<F, ?> alias) {
+        MPJLambdaWrapper<E> wrapper = new MPJLambdaWrapper<E>(null, clazz, SharedString.emptyString(), paramNameSeq, paramNameValuePairs,
+                new MergeSegments(), SharedString.emptyString(), SharedString.emptyString(), SharedString.emptyString(),
+                new TableList(), null, null, null, null) {
+        };
+        String st = "st";
+        wrapper.tableList.setAlias(st);
+        wrapper.alias = st;
+        wrapper.subTableAlias = st;
+        consumer.accept(wrapper);
+        String sql = WrapperUtils.buildSqlByWrapper(clazz, wrapper, alias);
+        this.selectColumns.add(new SelectString(sql, hasAlias, this.alias));
+        return typedThis;
+    }
+
     /**
      * 查询条件 SQL 片段
      */

mybatis-plus-join-test/test-join/src/test/java/com/github/yulichang/test/join/LambdaWrapperTest.java

@@ -1011,4 +1011,20 @@ class LambdaWrapperTest {
             //忽略异常 h2不支持连表删除
         }
     }
+
+    /**
+     * select 子查询
+     */
+    @Test
+    void sub() {
+        ThreadLocalUtils.set("SELECT ( SELECT st.id FROM `user` st WHERE st.del=false AND (st.id <= ?) limit 1 ) AS pid FROM `user` t LEFT JOIN address t1 ON (t1.user_id = t.id) WHERE t.del=false AND t1.del=false AND (t.id <= ?)");
+        MPJLambdaWrapper<UserDO> wrapper = JoinWrappers.lambda(UserDO.class)
+                .selectSub(UserDO.class, w -> w.select(UserDO::getId)
+                        .le(UserDO::getId,1000)
+                        .last("limit 1"), UserDO::getPid)
+                .leftJoin(AddressDO.class,AddressDO::getUserId,UserDO::getId)
+                .le(UserDO::getId,100);
+        wrapper.list();
+        System.out.println(1);
+    }
 }