如何用sqlbuilder建立SELECT查詢？

我使用Java和從http://openhms.sourceforge.net/sqlbuilder/ SQLBuilder，我試圖構建SQL SELECT查詢動態地：如何用sqlbuilder建立SELECT查詢？

SelectQuery sql = new SelectQuery(); 
sql.addAllColumns().addCustomFromTable("table1"); 
sql.addCondition(BinaryCondition.like("column1", "A"));

然而，它創建的字符串是這樣的：

SELECT * FROM table1 WHERE ('column1' LIKE 'A')

由於錯誤引號（'column1'）它無法正常工作。我想它預計在.like()方法中的某個Column對象。有沒有什麼辦法用適當的引號創建查詢？

來源

2016-09-25 Dmitry Kach

您應該使用列對象類型而不是「column1」字符串 –

@SergeiPodlipaev是的，我已經解決了它。無論如何感謝 –

我找到了解決辦法。我必須創建新類Column擴展CustomSql，並通過我的列名作爲參數：

public class Column extends CustomSql { 
    public Column(String str) { 
     super(str); 
    } 
}

然後：

SelectQuery sql = new SelectQuery(); 
sql.addAllColumns().addCustomFromTable("table1"); 
sql.addCondition(BinaryCondition.like(new Column("column1"), "A"));

或者沒有創建自己的類：

SelectQuery sql = new SelectQuery(); 
sql.addAllColumns().addCustomFromTable("table1"); 
sql.addCondition(BinaryCondition.like(new CustomSql("column1"), "A"));

它創建下面的SQL查詢，它工作正常：

SELECT * FROM table1 WHERE (column1 LIKE 'A')

來源

2016-09-26 10:11:55

BinaryCondition.like（）將Object取爲Column Object，然後在內部使用Converter.toColumnSqlObject(Object)將其轉換爲SqlObject。在Class DbTable和Class DbSchema中分別有一個名爲findColumn(String columnName)和findSchema(String tableName)的方法，您可以在其中傳遞一個簡單的字符串對象。試試這個會解決你的問題：

DbTable table1= schema.findSchema("table1"); 
DbColumn column1 = table1.findColumn("column1"); 

SelectQuery sql = new SelectQuery(); 
sql.addAllColumns().addCustomFromTable(table1); 
sql.addCondition(BinaryCondition.like(column1, "A"));

來源

2016-09-25 16:07:30 Shaggy

我沒有使用'DbSchema'來創建我的數據庫。我只需要構建一個查詢。可能嗎？ –

請檢查工作示例和重構自己的查詢

String query3 = 
     new SelectQuery() 
     .addCustomColumns(
      custNameCol, 
      FunctionCall.sum().addColumnParams(orderTotalCol)) 
     .addJoins(SelectQuery.JoinType.INNER, custOrderJoin) 
     .addCondition(BinaryCondition.like(custNameCol, "%bob%")) 
     .addCondition(BinaryCondition.greaterThan(
         orderDateCol, 
         JdbcEscape.date(new Date(108, 0, 1)), true)) 
     .addGroupings(custNameCol) 
     .addHaving(BinaryCondition.greaterThan(
        FunctionCall.sum().addColumnParams(orderTotalCol), 
        100, false)) 
     .validate().toString();

來源

2016-09-26 10:19:56

這個例子假設我已經使用模式對象創建了數據庫，但是我只需要構建一個查詢。看到我的答案 –

看看這個庫JDSQL（它需要Java 8）：

JQuery jquery = new JQuery(); 
    Collection<Map<String, Object>> result = jquery.select("tbl1::column1", "tbl2::column2") //Select column list 
               .from("Table1" , "TB1") // Specifiy main table entry, and you can add alias 
               .join("Table2::tb2") // Provide your join table, and another way to provide alias name 
               .on("tbl1.key1", "tbl2.key1") // your on statement will be based on the passed 2 values equaliy 
               .join("Table3", "tbl3", true) // Join another table with a flag to enable/disable the join (Lazy Joining) 
               .on("tbl2.key2", "tbl3.key1", (st-> {st.and("tbl3.condition = true"); return st;})) 
               .where("tbl1.condition", true, "!=") // Start your where statment and it also support enable/disable flags 
               .and("tbl2.condition = true", (st-> {st.or("tbl.cond2", 9000, "="); return st;})) // And statment that is grouping an or inside parentheses to group conditions 
               .and("tbl3.cond3=5", false) // And statment with a flag to enable/disable the condition 
               .get((String sql, Map<String, Object> parameters)-> getData(sql, parameters)); // Passing the hybrid getter. 
                   //You can also assign the getter at the jqueryobject itself by calling setGetter. 
} 

private static Collection<Map<String, Object>> getData(String sql, Map<String, Object> parameters){ 



    return null; 

}

}

來源

2016-09-29 16:57:42

如何用sqlbuilder建立SELECT查詢？

回答

相關問題