feat(postgresql): Added database user query function

chat2db-server/chat2db-plugins/chat2db-postgresql/src/main/java/ai/chat2db/plugin/postgresql/PostgreSQLMetaData.java

@@ -329,7 +329,7 @@ public class PostgreSQLMetaData extends DefaultMetaService implements MetaData {
                     if (resultSet.next()) {
                         String nspname = resultSet.getString("nspname");
                         String relname = resultSet.getString("relname");
-                        String typname = resultSet.getString("typname");
+                        String typname = getConversionType(resultSet.getString("typname"));
                         String seqcache = resultSet.getString("seqcache");
                         String rolname = resultSet.getString("rolname");
                         String comment = resultSet.getString("comment");
@@ -339,12 +339,6 @@ public class PostgreSQLMetaData extends DefaultMetaService implements MetaData {
                         String seqmin = resultSet.getString("seqmin");
                         Boolean seqcycle = resultSet.getBoolean("seqcycle");
 
-                        switch (typname) {
-                            case "int2" -> typname = "SMALLINT";
-                            case "int8" -> typname = "BIGINT";
-                            default -> typname = "INTEGER";
-                        }
-
                         stringBuilder.append(CREATE_SEQUENCE).append(getMetaDataName(nspname, relname)).append(NEW_LINE);
 
                         if (Double.compare(databaseProductVersion, 10.0) >= 0) {
@@ -406,7 +400,7 @@ public class PostgreSQLMetaData extends DefaultMetaService implements MetaData {
                 return Sequence.builder()
                         .nspname(resultSet.getString("nspname"))
                         .relname(resultSet.getString("relname"))
-                        .typname(resultSet.getString("typname"))
+                        .typname(getConversionType(resultSet.getString("typname")))
                         .seqcache(resultSet.getString("seqcache"))
                         .rolname(resultSet.getString("rolname"))
                         .comment(resultSet.getString("comment"))
@@ -420,4 +414,25 @@ public class PostgreSQLMetaData extends DefaultMetaService implements MetaData {
             return null;
         });
     }
+
+    @Override
+    public List<String> usernames(Connection connection) {
+        List<String> usernames = new ArrayList<>();
+        return SQLExecutor.getInstance().preExecute(connection, EXPORT_USERS_SQL, null, resultSet -> {
+            while (resultSet.next()) {
+                String username = resultSet.getString("username");
+                usernames.add(username);
+            }
+            return usernames;
+        });
+    }
+
+    private String getConversionType(String typname) {
+        switch (typname) {
+            case "int2" -> typname = "SMALLINT";
+            case "int8" -> typname = "BIGINT";
+            default -> typname = "INTEGER";
+        }
+        return typname;
+    }
 }

chat2db-server/chat2db-plugins/chat2db-postgresql/src/main/java/ai/chat2db/plugin/postgresql/consts/SQLConst.java

@@ -675,4 +675,10 @@ public class SQLConst {
                  pg_namespace n ON n.oid = c.relnamespace
             WHERE n.nspname = ?;
             """;
+
+	public static final String EXPORT_USERS_SQL = """
+			SELECT rolname AS username
+			FROM pg_roles
+			ORDER BY rolname;
+			""";
 }

chat2db-server/chat2db-server-domain/chat2db-server-domain-api/src/main/java/ai/chat2db/server/domain/api/service/DatabaseService.java

@@ -98,4 +98,11 @@ public interface DatabaseService {
      * @return
      */
     String exportDatabase(DatabaseExportParam param) throws SQLException;
+
+    /**
+     * Query the user under a database
+     *
+     * @return User list
+     */
+    ListResult<String> getUsernameList();
 }

chat2db-server/chat2db-server-domain/chat2db-server-domain-core/src/main/java/ai/chat2db/server/domain/core/impl/DatabaseServiceImpl.java

@@ -6,7 +6,6 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
-import java.util.function.Consumer;
 
 import ai.chat2db.server.domain.api.param.datasource.DatabaseCreateParam;
 import ai.chat2db.server.domain.api.param.datasource.DatabaseExportParam;
@@ -196,4 +195,10 @@ public class DatabaseServiceImpl implements DatabaseService {
         return "exportDatabase success";
     }
 
+    @Override
+    public ListResult<String> getUsernameList(){
+        MetaData metaSchema = Chat2DBContext.getMetaData();
+        List<String> usernames = metaSchema.usernames(Chat2DBContext.getConnection());
+        return ListResult.of(usernames);
+    }
 }

chat2db-server/chat2db-server-domain/chat2db-server-domain-core/src/main/java/ai/chat2db/server/domain/core/impl/SequenceServiceImpl.java

@@ -45,7 +45,7 @@ public class SequenceServiceImpl implements SequenceService {
 
     @Override
     public ListResult<Sql> buildSql(Sequence oldSequence, Sequence newSequence) {
-        SqlBuilder sqlBuilder = Chat2DBContext.getSqlBuilder();
+        SqlBuilder<?> sqlBuilder = Chat2DBContext.getSqlBuilder();
         List<Sql> sqls = new ArrayList<>();
         if (ObjectUtil.isEmpty(oldSequence)) {
             sqls.add(Sql.builder().sql(sqlBuilder.buildCreateSequenceSql(newSequence)).build());

chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/rdb/DatabaseController.java

@@ -150,4 +150,14 @@ public class DatabaseController {
         }
         return DataResult.of(task.getExportStatus());
     }
+
+    /**
+     * Query the database_user_list contained in the database
+     *
+     * @return username list
+     */
+    @GetMapping("/database_username_list")
+    public ListResult<String> databaseUsernameList(@Valid DataSourceBaseRequest dataSourceBaseRequest) {
+        return databaseService.getUsernameList();
+    }
 }

chat2db-server/chat2db-spi/src/main/java/ai/chat2db/spi/MetaData.java

@@ -292,4 +292,6 @@ public interface MetaData {
      */
     Sequence sequences(Connection connection, @NotEmpty String databaseName, String schemaName, String sequenceName);
 
+    List<String> usernames(Connection connection);
+
 }

chat2db-server/chat2db-spi/src/main/java/ai/chat2db/spi/jdbc/DefaultMetaService.java

@@ -12,6 +12,7 @@ import org.apache.commons.lang3.StringUtils;
 
 import java.sql.Connection;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -196,11 +197,16 @@ public class DefaultMetaService implements MetaData {
 
     @Override
     public List<SimpleSequence> sequences(Connection connection, String databaseName, String schemaName){
-        return null;
+        return Collections.emptyList();
     }
 
     @Override
     public Sequence sequences(Connection connection, @NotEmpty String databaseName, String schemaName, String sequenceName){
         return null;
     }
+
+    @Override
+    public List<String> usernames(Connection connection){
+        return Collections.emptyList();
+    }
 }

chat2db-server/chat2db-spi/src/main/java/ai/chat2db/spi/sql/SQLExecutor.java

@@ -14,7 +14,9 @@ import ai.chat2db.spi.model.*;
 import ai.chat2db.spi.util.JdbcUtils;
 import ai.chat2db.spi.util.ResultSetUtils;
 import ai.chat2db.spi.util.SqlUtils;
+import cn.hutool.core.collection.CollectionUtil;
 import cn.hutool.core.date.TimeInterval;
+import cn.hutool.core.util.ArrayUtil;
 import com.alibaba.druid.DbType;
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLStatement;
@@ -125,10 +127,12 @@ public class SQLExecutor implements CommandExecutor {
     }
 
     public <R> R preExecute(Connection connection, String sql, String[] args, ResultSetFunction<R> function) {
-        log.info("execute:{}", sql);
+        log.info("preExecute:{}", sql);
         try (PreparedStatement preparedStatement = connection.prepareStatement(sql)) {
-            for (int i = 0; i < args.length; i++) {
+            if (ArrayUtil.isNotEmpty(args)) {
-                preparedStatement.setObject(i + 1, args[i]);
+                for (int i = 0; i < args.length; i++) {
+                    preparedStatement.setObject(i + 1, args[i]);
+                }
             }
             boolean query = preparedStatement.execute();
             // Represents the query
@@ -642,7 +646,7 @@ public class SQLExecutor implements CommandExecutor {
         }
         return executeResult;
     }
-    
+
     /**
      * Formats the given table name by stripping off any schema or catalog prefixes.
      * If the table name contains a dot ('.'), it splits the string by the dot