添加oracle和sql server的分页语句

tian-junwei · Aug 18, 2016 · fe46bcb · fe46bcb
1 parent e742378
commit fe46bcb
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Showing 4 changed files with 148 additions and 12 deletions.
diff --git a/src/main/java/com/tianjunwei/page/dialect/OracleDialect.java b/src/main/java/com/tianjunwei/page/dialect/OracleDialect.java
@@ -1,5 +1,8 @@
 package com.tianjunwei.page.dialect;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 import org.apache.ibatis.mapping.MappedStatement;
 import org.apache.ibatis.session.RowBounds;
 
@@ -11,7 +14,13 @@ public OracleDialect(MappedStatement mappedStatement,
 	}
 
 	/**   
-	 *  
+	 * <blockquote><pre>
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =1;
+     * 结果：return "select * from ( select row_.*, rownum rownum_ from ( select * from table order by i_id asc ) row_ ) where rownum_ <=11 and rownum_ > 1";
+     * 或者
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =0;
+     * 结果：return "select * from ( select * from table order by i_id asc ) where rownum <= 10";
+     * </blockquote></pre>
 	 * @param sql
 	 * @param offsetName
 	 * @param offset
@@ -22,8 +31,38 @@ public OracleDialect(MappedStatement mappedStatement,
 	 */ 
 	@Override
 	protected String getLimitString(String sql, String offsetName, int offset, String limitName, int limit) {
-		// TODO Auto-generated method stub
-		return null;
+
+		sql = sql.trim();
+		boolean isForUpdate = false;
+        Pattern p = Pattern.compile("\t|\r|\n");
+        Matcher m = p.matcher(sql);
+        sql = m.replaceAll(" ");
+        sql = sql.replaceAll(" +", " ");
+
+		if ( sql.toLowerCase().endsWith(" for update") ) {
+			sql = sql.substring( 0, sql.length()-11 );
+			isForUpdate = true;
+		}
+		StringBuffer pagingSelect = new StringBuffer( sql.length()+100 );
+		if (offset > 0) {
+			pagingSelect.append("select * from ( select row_.*, rownum rownum_ from ( ");
+		}else {
+			pagingSelect.append("select * from ( ");
+		}
+		pagingSelect.append(sql);
+		if (offset > 0) {
+			pagingSelect.append(" ) row_ ) where rownum_ <= ? and rownum_ > ?");
+            setPageParameter("__offsetEnd",offset+limit,Integer.class);
+            setPageParameter(offsetName,offset,Integer.class);
+		}else {
+			pagingSelect.append(" ) where rownum <= ?");
+            setPageParameter(limitName,limit,Integer.class);
+		}
+		if ( isForUpdate ) {
+			pagingSelect.append( " for update" );
+		}
+
+		return pagingSelect.toString();
 	}
 
 }
diff --git a/src/main/java/com/tianjunwei/page/dialect/Sqlserver2005Dialect.java b/src/main/java/com/tianjunwei/page/dialect/Sqlserver2005Dialect.java
@@ -11,7 +11,13 @@ public Sqlserver2005Dialect(MappedStatement mappedStatement,
 	}
 
 	/**   
-	 *  
+	 * <blockquote><pre>
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =1;
+     * 结果：return "WITH query AS (SELECT TOP 100 PERCENT  ROW_NUMBER() OVER (order by i_id asc) as __row_number__,  * from table order by i_id asc) SELECT * FROM query WHERE __row_number__ > 1 AND __row_number__ <= 11 ORDER BY __row_number__";
+     * 或者
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =0;
+     * 结果：return "WITH query AS (SELECT TOP 100 PERCENT  ROW_NUMBER() OVER (order by i_id asc) as __row_number__,  * from table order by i_id asc) SELECT * FROM query WHERE __row_number__ > 0 AND __row_number__ <= 10 ORDER BY __row_number__";
+     * </blockquote></pre>
 	 * @param sql
 	 * @param offsetName
 	 * @param offset
@@ -22,8 +28,48 @@ public Sqlserver2005Dialect(MappedStatement mappedStatement,
 	 */ 
 	@Override
 	protected String getLimitString(String sql, String offsetName, int offset, String limitName, int limit) {
-		// TODO Auto-generated method stub
-		return null;
+		StringBuffer pagingBuilder = new StringBuffer();
+		String orderby = getOrderByPart(sql);
+		String distinctStr = "";
+		String loweredString = sql.toLowerCase();
+		String sqlPartString = sql;
+		if (loweredString.trim().startsWith("select")) {
+			int index = 6;
+			if (loweredString.startsWith("select distinct")) {
+				distinctStr = "DISTINCT ";
+				index = 15;
+			}
+			sqlPartString = sqlPartString.substring(index);
+		}
+		pagingBuilder.append(sqlPartString);
+		// if no ORDER BY is specified use fake ORDER BY field to avoid errors
+		if (orderby == null || orderby.length() == 0) {
+			orderby = "ORDER BY CURRENT_TIMESTAMP";
+		}
+		StringBuffer result = new StringBuffer();
+		result.append("WITH query AS (SELECT ")
+				.append(distinctStr)
+				.append("TOP 100 PERCENT ")
+				.append(" ROW_NUMBER() OVER (")
+				.append(orderby)
+				.append(") as __row_number__, ")
+				.append(pagingBuilder)
+				.append(") SELECT * FROM query WHERE __row_number__ > ? AND __row_number__ <= ?")
+				.append(" ORDER BY __row_number__");
+        setPageParameter(offsetName,offset,Integer.class);
+        setPageParameter("__offsetEnd",offset+limit,Integer.class);
+		return result.toString();
+	}
+	static String getOrderByPart(String sql) {
+		String loweredString = sql.toLowerCase();
+		int orderByIndex = loweredString.indexOf("order by");
+		if (orderByIndex != -1) {
+			// if we find a new "order by" then we need to ignore
+			// the previous one since it was probably used for a subquery
+			return sql.substring(orderByIndex);
+		} else {
+			return "";
+		}
 	}
 
 }
diff --git a/src/main/java/com/tianjunwei/page/dialect/Sqlserver2008Dialect.java b/src/main/java/com/tianjunwei/page/dialect/Sqlserver2008Dialect.java
@@ -4,14 +4,24 @@
 import org.apache.ibatis.session.RowBounds;
 
 public class Sqlserver2008Dialect extends Dialect{
+
+	private static final String ORDERBY = "order by";
+	private static final String SELECT = "select";
+	private static final String SELECT_DISTINCT = "select distinct";
 
 	public Sqlserver2008Dialect(MappedStatement mappedStatement,
 			Object parameterObject, RowBounds pageBounds) {
 		super(mappedStatement, parameterObject, pageBounds);
 	}
 
 	/**   
-	 *  
+	 * <blockquote><pre>
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =1;
+     * 结果：return "WITH page_query AS (select ROW_NUMBER() OVER (order by i_id asc) as row_nr__, * from table ) SELECT * FROM page_query WHERE row_nr__ between 2 and 11";
+     * 或者
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =0;
+     * 结果：return "select top 10 * from table order by i_id asc ";
+     * </blockquote></pre>
 	 * @param sql
 	 * @param offsetName
 	 * @param offset
@@ -22,8 +32,38 @@ public Sqlserver2008Dialect(MappedStatement mappedStatement,
 	 */ 
 	@Override
 	protected String getLimitString(String sql, String offsetName, int offset, String limitName, int limit) {
-		// TODO Auto-generated method stub
-		return null;
+		String newsql="";
+		 if(offset == 0){
+			 newsql= new StringBuffer( sql.length() + 8 )
+						.append( sql )
+						.insert( getAfterSelectInsertPoint( sql ), " top " + limit )
+						.toString();
+			 return newsql;
+		    }else{
+				int endIndex = offset + limit;
+				StringBuilder sb = new StringBuilder(sql.replaceAll("\\s{2,}", " ").toLowerCase().trim());
+				if(sb.indexOf(SELECT_DISTINCT)==sb.indexOf(SELECT)){
+					throw new UnsupportedOperationException(getClass().getName()+".getLimitString(String queryString, int limit, int offset) unsupport key DISTINCT in query");
+				}
+				int orderByIndex = sb.indexOf(ORDERBY);
+				//判断queryString中是否有order by 若没有则创建。
+				CharSequence orderby = orderByIndex > 0 ? sb.subSequence(orderByIndex, sb.length()) : " order by CURRENT_TIMESTAMP";
+				if(orderByIndex > 0){
+					//原句中有orderby时将其提取至Over()内
+					sb.delete(orderByIndex, orderByIndex + orderby.length());
+				}
+				int selectEndIndex = sb.indexOf(SELECT) + SELECT.length();
+				//构建分页sql
+				sb.insert(selectEndIndex, " ROW_NUMBER() OVER (" + orderby + ") as row_nr__,");
+				sb.insert(0, "WITH page_query AS (").append(") SELECT * FROM page_query ");
+				sb.append("WHERE row_nr__ between ").append(offset+1).append(" and ").append(endIndex);
+				return sb.toString();
+		    }
+	}
+	static int getAfterSelectInsertPoint(String sql) {
+		int selectIndex = sql.toLowerCase().indexOf( "select" );
+		final int selectDistinctIndex = sql.toLowerCase().indexOf( "select distinct" );
+		return selectIndex + ( selectDistinctIndex == selectIndex ? 15 : 6 );
 	}
 
 }
diff --git a/src/main/java/com/tianjunwei/page/dialect/Sqlserver2012Dialect.java b/src/main/java/com/tianjunwei/page/dialect/Sqlserver2012Dialect.java
@@ -11,7 +11,13 @@ public Sqlserver2012Dialect(MappedStatement mappedStatement,
 	}
 
 	/**   
-	 *  
+	 * <blockquote><pre>
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =1;
+     * 结果：return "select * from table order by i_id asc offset 1 row fetch next 10 rows only";
+     * 或者
+     * 参数：sql = " select * from table order by i_id asc"; limit=10; offset =0;
+     * 结果：return "select * from table order by i_id asc offset 0 row fetch next 10 rows only";
+     * </blockquote></pre> 
 	 * @param sql
 	 * @param offsetName
 	 * @param offset
@@ -22,8 +28,13 @@ public Sqlserver2012Dialect(MappedStatement mappedStatement,
 	 */ 
 	@Override
 	protected String getLimitString(String sql, String offsetName, int offset, String limitName, int limit) {
-		// TODO Auto-generated method stub
-		return null;
+		sql = new StringBuilder(sql)
+	    		.append(" offset ")
+	    		.append(offset)
+	    		.append(" row fetch next ")
+	    		.append(limit)
+	    		.append(" rows only").toString();
+		return sql;
 	}
 
 }