Merge pull request #570 from fangzhengjin/feat-QueryMethods

feat: 增加STRING_AGG、LISTAGG、CAST函数支持

mybatis-flex-core/src/main/java/com/mybatisflex/core/constant/FuncName.java

@@ -144,6 +144,9 @@ public class FuncName {
     public static final String WEEKOFYEAR = "WEEKOFYEAR";
     public static final String YEAR = "YEAR";
     public static final String GROUP_CONCAT = "GROUP_CONCAT";
+    public static final String STRING_AGG = "STRING_AGG";
+    public static final String LISTAGG = "LISTAGG";
+
     private FuncName() {
     }
 

mybatis-flex-core/src/main/java/com/mybatisflex/core/dialect/DbType.java

@@ -17,6 +17,7 @@ package com.mybatisflex.core.dialect;
 
 import com.mybatisflex.core.util.StringUtil;
 import java.util.Arrays;
+import java.util.List;
 
 public enum DbType {
 
@@ -208,4 +209,44 @@ public enum DbType {
             .findFirst()
             .orElse(null);
     }
+
+    /**
+     * 获取所有数据库类型
+     *
+     * @return 包含所有数据库类型的列表
+     */
+    public static List<DbType> all() {
+        return Arrays.asList(DbType.values());
+    }
+
+    /**
+     * 判断当前数据库语法是否与MySQL属于同一类型
+     */
+    public boolean mysqlSameType() {
+        return this == MYSQL || this == MARIADB || this == GBASE || this == OSCAR || this == XUGU || this == CLICK_HOUSE || this == OCEAN_BASE || this == CUBRID || this == SUNDB || this == GOLDENDB || this == YASDB;
+    }
+
+    /**
+     * 判断当前数据库语法是否与Oracle属于同一类型
+     */
+    public boolean oracleSameType() {
+        return this == ORACLE || this == DM;
+    }
+
+    /**
+     * 判断当前数据库语法是否与PostgreSQL属于同一类型
+     */
+    public boolean postgresqlSameType() {
+        return this == POSTGRE_SQL || this == H2 || this == LEALONE || this == SQLITE || this == HSQL || this == KINGBASE_ES || this == PHOENIX || this == SAP_HANA || this == IMPALA || this == HIGH_GO || this == VERTICA || this == REDSHIFT || this == GAUSS || this == OPENGAUSS || this == TDENGINE || this == UXDB || this == GBASE_8S_PG || this == GBASE_8C || this == VASTBASE || this == DUCKDB;
+    }
+
+    /**
+     * 是否为已兼容的数据库类型
+     * 允许的数据库类型包括MySQL系列、Oracle系列和PostgreSQL系列
+     *
+     * @return 如果是允许的数据库类型返回true，否则返回false
+     */
+    public boolean isSupportDb() {
+        return mysqlSameType() || oracleSameType() || postgresqlSameType();
+    }
 }

mybatis-flex-core/src/main/java/com/mybatisflex/core/dialect/DbTypeUtil.java

@@ -16,6 +16,7 @@
 package com.mybatisflex.core.dialect;
 
 
+import com.mybatisflex.core.FlexGlobalConfig;
 import com.mybatisflex.core.exception.FlexExceptions;
 import com.mybatisflex.core.exception.locale.LocalizedFormats;
 import com.mybatisflex.core.util.StringUtil;
@@ -37,6 +38,20 @@ public class DbTypeUtil {
     private DbTypeUtil() {
     }
 
+    /**
+     * 获取当前数据库类型
+     * <p>首先从全局配置中获取数据库类型，如果全局配置中未设置，则尝试从方言工厂中获取线程局部变量设置的数据库类型
+     *
+     * @return 当前数据库类型，可能为null
+     */
+    public static DbType getCurrentDbType() {
+        DbType dbType = FlexGlobalConfig.getDefaultConfig().getDbType();
+        if (dbType == null) {
+            dbType = DialectFactory.getHintDbType();
+        }
+        return dbType;
+    }
+
     /**
      * 获取当前配置的 DbType
      */

mybatis-flex-core/src/main/java/com/mybatisflex/core/query/CastQueryColumn.java

@@ -0,0 +1,74 @@
+/*
+ *  Copyright (c) 2022-2024, Mybatis-Flex (fuhai999@gmail.com).
+ *  <p>
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *  <p>
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *  <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package com.mybatisflex.core.query;
+
+import com.mybatisflex.core.FlexConsts;
+import com.mybatisflex.core.dialect.IDialect;
+
+import java.util.List;
+
+/**
+ * CAST函数查询列
+ */
+public class CastQueryColumn extends QueryColumn implements HasParamsColumn {
+
+    private QueryColumn column;
+    private final String dataType;
+
+    public CastQueryColumn(QueryColumn column, String dataType) {
+        this.column = column;
+        this.dataType = dataType;
+    }
+
+    public CastQueryColumn(String column, String dataType) {
+        this.column = new QueryColumn(column);
+        this.dataType = dataType;
+    }
+
+    @Override
+    protected String toConditionSql(List<QueryTable> queryTables, IDialect dialect) {
+        return " CAST(" + column.toConditionSql(queryTables, dialect) + " AS " + dataType + ") ";
+    }
+
+    @Override
+    protected String toSelectSql(List<QueryTable> queryTables, IDialect dialect) {
+        return " CAST(" + column.toSelectSql(queryTables, dialect) + " AS " + dataType + ") " + WrapperUtil.buildColumnAlias(alias, dialect);
+    }
+
+    @Override
+    public CastQueryColumn clone() {
+        CastQueryColumn clone = (CastQueryColumn) super.clone();
+        clone.column = column.clone();
+        return clone;
+    }
+
+    @Override
+    public String toString() {
+        return "CastQueryColumn{" +
+            "column=" + column +
+            ", dataType='" + dataType + '\'' +
+            ", alias='" + alias + '\'' +
+            '}';
+    }
+
+    @Override
+    public Object[] getParamValues() {
+        if (column instanceof HasParamsColumn) {
+            return ((HasParamsColumn) column).getParamValues();
+        }
+        return FlexConsts.EMPTY_ARRAY;
+    }
+}

mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryColumn.java

@@ -955,6 +955,10 @@ public class QueryColumn implements CloneSupport<QueryColumn>, Conditional<Query
         return new ArithmeticQueryColumn(this).divide(number);
     }
 
+    public QueryColumn cast(String dataType) {
+        return new CastQueryColumn(this, dataType);
+    }
+
     /**
      * 生成列用于构建查询条件的 SQL 语句。
      *

mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryMethods.java

@@ -2678,6 +2678,51 @@ public class QueryMethods {
         return new FunctionQueryColumn(GROUP_CONCAT, columnX);
     }
 
+    /**
+     * STRING_AGG 聚合函数
+     */
+    public static QueryColumn stringAgg(QueryColumn columnX, String separator) {
+        return new FunctionQueryColumn(STRING_AGG, columnX, string(separator));
+    }
+
+    public static QueryColumn stringAgg(String columnX, String separator) {
+        return new FunctionQueryColumn(STRING_AGG, columnX, separator);
+    }
+
+    public static <T> QueryColumn stringAgg(LambdaGetter<T> columnX, String separator) {
+        return new FunctionQueryColumn(STRING_AGG, LambdaUtil.getQueryColumn(columnX), string(separator));
+    }
+
+    /**
+     * LISTAGG 聚合函数
+     */
+    public static QueryColumn listAgg(QueryColumn column, String separator) {
+        return new FunctionQueryColumn(LISTAGG, column, string(separator));
+    }
+
+    public static QueryColumn listAgg(String column, String separator) {
+        return new FunctionQueryColumn(STRING_AGG, column, separator);
+    }
+
+    public static <T> QueryColumn listAgg(LambdaGetter<T> column, String separator) {
+        return new FunctionQueryColumn(STRING_AGG, LambdaUtil.getQueryColumn(column), string(separator));
+    }
+
+    /**
+     * CAST函数查询列
+     */
+    public static <T> QueryColumn cast(QueryColumn column, String dataType) {
+        return new CastQueryColumn(column, dataType);
+    }
+
+    public static <T> QueryColumn cast(String column, String dataType) {
+        return new CastQueryColumn(column, dataType);
+    }
+
+    public static <T> QueryColumn cast(LambdaGetter<T> column, String dataType) {
+        return new CastQueryColumn(LambdaUtil.getQueryColumn(column), dataType);
+    }
+
     /**
      * date 函数
      * @return