獲得結果集的行數

Question

請幫助!!!!!!! 在數據庫我有2行與此查詢。

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SELECT D.DEALER_CODE 
FROM SCOTT.T_DEALERSHIP D,SCOTT.T_DEALER_BILLING DB 
WHERE D.DEALER_CODE = DB.DEALER_CODE 
    AND DEALER_NAME LIKE 'XTIME%' 
    AND (RNR_CUST_NUM = '546' OR RNR_CUST_NUM = '43356'OR RNR_CUST_NUM = '7637055' OR RNR_CUST_NUM ='7637055' OR RNR_CUST_NUM IS NULL) 
    AND (RCI_STORE_NUMBER IS NULL OR RCI_STORE_NUMBER = '05') 
    AND (RCI_AREA_NUMBER = '01'OR RCI_AREA_NUMBER IS NULL) 
    AND (RCI_DEALER_NUMBER IS NULL AND DEALER_Address1 LIKE UPPER('1500 ORACLE%')         
    AND DEALER_CITY =UPPER('BAKERSFIELD') AND DEALER_ZIP LIKE'6%') 

下面的代碼，我只得到1行的時候有2條記錄在數據庫中。當數據庫中只有一條記錄時，只有一條記錄有效，但當有更多記錄時不起作用。另外rs.last()方法被跳過並退出結果集。我必須評論它執行一條記錄。我不想使用COUNT。

ResultSet rs = stmt.executeQuery(sql1); 
System.out.println("" + sql1); 

while(rs.next()) { 
    rs.last(); 
    int Rows = rs.getRow(); 
    System.out.println("Rows are " + Rows); 
} 

Answer 1

如果你想要做的就是在統計數據庫中的記錄，那麼你真的應該使用形式SELECT count(*) FROM ...的查詢。如果你真的需要執行查詢你上面列出的方式，那麼你想設置一個計數器變量您while循環之外，像這樣：

int rowNum = 0; 
while (rs.next()) { 
    rowNum++; 
} 
System.out.println("Number of records: "+rowNum); 

Answer 2

我強烈反對通過JDBC返回所有的數據到Java剛確定行數。如果你只是想知道有多少行符合條件，然後做一個SELECT COUNT（*）查詢：

在SQL：

SELECT COUNT(*) 
FROM SCOTT.T_DEALERSHIP D,SCOTT.T_DEALER_BILLING DB 
WHERE D.DEALER_CODE = DB.DEALER_CODE 
    AND DEALER_NAME LIKE 'XTIME%' 
    AND (RNR_CUST_NUM = '546' OR RNR_CUST_NUM = '43356'OR RNR_CUST_NUM = '7637055' OR RNR_CUST_NUM ='7637055' OR RNR_CUST_NUM IS NULL) 
    AND (RCI_STORE_NUMBER IS NULL OR RCI_STORE_NUMBER = '05') 
    AND (RCI_AREA_NUMBER = '01'OR RCI_AREA_NUMBER IS NULL) 
    AND (RCI_DEALER_NUMBER IS NULL AND DEALER_Address1 LIKE UPPER('1500 ORACLE%') 
    AND DEALER_CITY =UPPER('BAKERSFIELD') AND DEALER_ZIP LIKE'6%') 

然後在Java中：

ResultSet rs = stmt.executeQuery(sql1); 
System.out.println("" + sql1); 

int rows = 0; 
if(rs.next()) { 
    rows = rs.getInt(); 
} 
System.out.println("Rows are " + rows); 

編輯基於OP的評論

要從數據庫除了計數以外的值，只需掃描值。

SQL：

SELECT D.DEALER_CODE 
FROM SCOTT.T_DEALERSHIP D,SCOTT.T_DEALER_BILLING DB 
WHERE D.DEALER_CODE = DB.DEALER_CODE 
    AND DEALER_NAME LIKE 'XTIME%' 
    AND (RNR_CUST_NUM = '546' OR RNR_CUST_NUM = '43356'OR RNR_CUST_NUM = '7637055' OR RNR_CUST_NUM ='7637055' OR RNR_CUST_NUM IS NULL) 
    AND (RCI_STORE_NUMBER IS NULL OR RCI_STORE_NUMBER = '05') 
    AND (RCI_AREA_NUMBER = '01'OR RCI_AREA_NUMBER IS NULL) 
    AND (RCI_DEALER_NUMBER IS NULL AND DEALER_Address1 LIKE UPPER('1500 ORACLE%') 
    AND DEALER_CITY =UPPER('BAKERSFIELD') AND DEALER_ZIP LIKE'6%') 

的Java：

ResultSet rs = stmt.executeQuery(sql1); 
System.out.println("" + sql1); 

List<String> rows = new ArrayList<String>(); 
while(rs.next()) { 
    rows.add(rs.getString()); 
} 
System.out.println("There are " + rows.size() + " rows.");