解决count(distinct var)问题

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/enums/SqlMethod.java

@@ -65,7 +65,7 @@ public enum SqlMethod {
     SELECT_BY_MAP("selectByMap", "根据columnMap 查询一条数据", "<script>\nSELECT %s FROM %s %s\n</script>"),
     SELECT_BATCH_BY_IDS("selectBatchIds", "根据ID集合，批量查询数据", "<script>\nSELECT %s FROM %s WHERE %s IN (%s)\n</script>"),
     SELECT_ONE("selectOne", "查询满足条件一条数据", "<script>\nSELECT %s FROM %s %s\n</script>"),
-    SELECT_COUNT("selectCount", "查询满足条件总记录数", "<script>\nSELECT COUNT(1) FROM %s %s\n</script>"),
+    SELECT_COUNT("selectCount", "查询满足条件总记录数", "<script>\nSELECT COUNT(%s) FROM %s %s\n</script>"),
     SELECT_LIST("selectList", "查询满足条件所有数据", "<script>\nSELECT %s FROM %s %s\n</script>"),
     SELECT_PAGE("selectPage", "查询满足条件所有数据（并翻页）", "<script>\nSELECT %s FROM %s %s\n</script>"),
     SELECT_MAPS("selectMaps", "查询满足条件所有数据", "<script>\nSELECT %s FROM %s %s\n</script>"),

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/injector/AbstractMethod.java

@@ -114,6 +114,18 @@ public abstract class AbstractMethod implements Constants {
             SqlScriptUtils.unSafeParam(Q_WRAPPER_SQL_SELECT), selectColumns);
     }
 
+    /**
+     * <p>
+     * SQL 查询记录行数
+     * </p>
+     *
+     * @return count sql 脚本
+     */
+    protected String sqlCount() {
+        return SqlScriptUtils.convertChoose(String.format("%s != null and %s != null", WRAPPER, Q_WRAPPER_SQL_SELECT),
+            SqlScriptUtils.unSafeParam(Q_WRAPPER_SQL_SELECT), ONE);
+    }
+
     /**
      * <p>
      * SQL 设置selectObj sql select

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/injector/methods/SelectCount.java

@@ -34,7 +34,7 @@ public class SelectCount extends AbstractMethod {
     @Override
     public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
         SqlMethod sqlMethod = SqlMethod.SELECT_COUNT;
-        String sql = String.format(sqlMethod.getSql(), tableInfo.getTableName(), this.sqlWhereEntityWrapper(true, tableInfo));
+        String sql = String.format(sqlMethod.getSql(), this.sqlCount(), tableInfo.getTableName(), this.sqlWhereEntityWrapper(true, tableInfo));
         SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
         return this.addSelectMappedStatement(mapperClass, sqlMethod.getMethod(), sqlSource, Integer.class, null);
     }

mybatis-plus-extension/src/main/java/com/baomidou/mybatisplus/extension/injector/methods/LogicSelectCount.java

@@ -34,7 +34,7 @@ public class LogicSelectCount extends AbstractLogicMethod {
     @Override
     public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
         SqlMethod sqlMethod = SqlMethod.SELECT_COUNT;
-        String sql = String.format(sqlMethod.getSql(), tableInfo.getTableName(), sqlWhereEntityWrapper(true, tableInfo));
+        String sql = String.format(sqlMethod.getSql(), this.sqlCount(), tableInfo.getTableName(), sqlWhereEntityWrapper(true, tableInfo));
         SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
         return addSelectMappedStatement(mapperClass, sqlMethod.getMethod(), sqlSource, Integer.class, null);
     }