Question

我创建了一个获取nvarchar的过程，并使用like返回一个表，它运行良好。但是当我想在java中使用这个过程时它不起作用。这是java代码。

  String query = "exec Predict ?";
  pst = conn.prepareStatement(query);
  pst.setString(1, "%"+"ee"+"%");

  rs = pst.executeQuery();
  int i = 0;
  while (rs.next()) {
    System.out.println(rs.getString(1));
    i++;
   }

Answer 1

嘿，你实际上不能把它称为查询。你必须使它成为一个可调用的语句并执行它。这是我一直在使用的代码。它也接受参数，但如果你不需要它，只需删除它。这是为我的项目设置定制的，但这将帮助你：

/** 
     * This method takes in a stored procedure along with its parameters and parameter type and creates a result set from them.
     * @param storedProcedure
     * @param parameters
     * @param parameterType
     * @return
     * @throws SQLException
     */
    public static ResultSet createRSFromStoredProc(String storedProcedure, ArrayList<String> parameters, ArrayList<String> parameterType) throws SQLException {

        // Initializes variables that are used in the method.
        Connection dbConnection = null;
        CallableStatement callableStatement = null;
        ResultSet rs = null;

        // Builds the stored procedure calling
        String insertStoreProc = "{call " + storedProcedure + "(";
        for(int i=0;i<parameters.size(); i++)
        {
            if(i==parameters.size()-1)
                insertStoreProc+="?";
            else
                insertStoreProc+="?,";
        }
        insertStoreProc+=")}";


        try {
            // establishes the connection
            dbConnection = getDBConnection();

            // creates the callable statement
            callableStatement = dbConnection.prepareCall(insertStoreProc);

            // Parses the string into the correct parameter type and sets the parameter to the value.
            for(int i=0;i<parameters.size(); i++)
            {
                if(parameterType.get(i).equals("string"))
                    callableStatement.setString(i+1, parameters.get(i));
                else if(parameterType.get(i).equals("int"))
                    callableStatement.setInt(i+1, Integer.parseInt(parameters.get(i)));
                if(parameterType.get(i).equals("dateTime"))
                {
                    // if now is entered for the time gets the current timestamp
                    if(parameters.get(i).equals("now"))
                        callableStatement.setTimestamp(i+1, Timestamp.valueOf(getCurrentDate()));
                    else
                    {
                        callableStatement.setString(i+1, parameters.get(i));
                    }

                }   
            }

            // execute insertDBUSER store procedure
            Boolean results = callableStatement.execute();
            int rowsAffected=0;
            while(results||rowsAffected!=-1)
            {
                if(results)
                {
                    rs=callableStatement.getResultSet();
                    break;
                }
                else
                {
                    rowsAffected=callableStatement.getUpdateCount();
                }
                results= callableStatement.getMoreResults();
            }


        } catch (SQLException e) {

            System.out.println(e.getMessage());

        } 
        return rs;

    }

在java中使用sql

1 个答案: