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h2数据库作为嵌入式数据库，使用起来非常方便，当然非常轻量。不太适用复杂的业务。
下面介绍一下，Java中对于h2数据库的增删改查。h2的搭建另有文章介绍
如下本人所写方法，主要供各位参考，仅用作学习研究，由需要的各位可以自行优化修改。
public class CommonDao {
/**
* 建表方法
* @param tableName
* @param items
* @return
* @throws SQLException
*/
public static Boolean crateTable(String tableName,String[] items) throws SQLException {
Connection conn = null;
Statement stmt = null;
try {
conn = ConnectionPool.getInstance().getConnection();
DatabaseMetaData meta = conn.getMetaData();
ResultSet rsTables = meta.getTables(null, null, tableName,
new String[] { "TABLE" });
if (!rsTables.next()) {
stmt = conn.createStatement();
StringBuilder sql = new StringBuilder();
sql.append(" CREATE TABLE ");
if (StringUtils.isNotEmpty(tableName)) {
sql.append(tableName);
}
if (items != null && items.length > 0) {
sql.append(" ( ");
sql.append(" hid VARCHAR(1024), ");
for (int i = 0;i < items.length;i++) {
sql.append(items[i]);
sql.append(" VARCHAR(5000), ");
}
sql.append("PRIMARY KEY(hid)) ");
}
stmt.execute(sql.toString());
}
rsTables.close();
return true;
} finally {
releaseConnection(conn, stmt, null);
}
}
/**
* h2数据库插入数据
* @param tableName
* @param items
* @param values
* @return
* @throws SQLException
*/
public static Boolean insertH2(String tableName,String[] items,String[] values) throws SQLException{
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
try {
conn = ConnectionPool.getInstance().getConnection();
StringBuilder sql = new StringBuilder();
sql.append(" INSERT INTO ");
if (StringUtils.isNotEmpty(tableName)) {
sql.append(tableName);
}
if (items != null && items.length > 0) {
sql.append(" ( ");
sql.append(" hid, ");
String strItems= StringUtils.join(items, ",");
sql.append(strItems);
sql.append(" ) ");
sql.append(" VALUES( ?,");
for (int i = 0;i < items.length;i++) {
sql.append("? ");
if (i < items.length - 1){
sql.append(", ");
}
}
sql.append(") ");
}
stmt = conn
.prepareStatement(sql.toString());
// values
stmt.setString(1, StringUtil.getUUID());
if (values != null && values.length > 0) {
for (int i = 0;i < values.length;i++) {
stmt.setString(i+2, values[i]);
}
}
return stmt.execute();
} finally {
conn.commit();
releaseConnection(conn, stmt, rs);
}
}
/**
* 查询方法
* @param tableName
* @param items
* @param params
* @return
* @throws SQLException
*/
public static List<Map<String,String>> selectH2(String tableName,String[] items,Map<String,String> params)throws SQLException {
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
List<Map<String,String>> result = new ArrayList<Map<String, String>>();
try {
conn = ConnectionPool.getInstance().getConnection();
StringBuilder sql = new StringBuilder();
sql.append(" Select ");
if (items != null && items.length > 0) {
String strItems= StringUtils.join(items, ",");
sql.append(strItems);
}
sql.append(" FROM ");
if (StringUtils.isNotEmpty(tableName)) {
sql.append(tableName);
}
// 存在查询条件
if (params != null && params.size() > 0) {
sql.append(" WHERE ");
Set<String> kSet = params.keySet();
for (String key:kSet) {
sql.append(key);
sql.append(" = ? and ");
}
sql.append("1 = 1");
}
stmt = conn
.prepareStatement(sql.toString());
// 存在查询条件
if (params != null && params.size() > 0) {
Set<String> kSet = params.keySet();
Integer index = 1;
for (String key:kSet) {
stmt.setString(index, params.get(key));
index++;
}
}
rs = stmt.executeQuery();
while (rs.next()) {
Map<String,String> resultMap = new HashMap<String, String>();
for (int i = 0;i < items.length;i++) {
resultMap.put(items[i],rs.getString(items[i]));
}
result.add(resultMap);
}
return result;
} finally {
releaseConnection(conn, stmt, rs);
}
}
/**
* 自定义sql
* @param sql
* @param items
* @param params
* @return
* @throws SQLException
*/
public static List<Map<String,String>> selectH2BySql(String sql,List<String> items,List<String> params)throws SQLException {
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
List<Map<String,String>> result = new ArrayList<Map<String, String>>();
try {
conn = ConnectionPool.getInstance().getConnection();
stmt = conn
.prepareStatement(sql);
// 存在查询条件
if (params != null && params.size() > 0) {
for (int i = 0;i < params.size();i++) {
stmt.setString(i+1,params.get(i));
}
}
rs = stmt.executeQuery();
while (rs.next()) {
Map<String,String> resultMap = new HashMap<String, String>();
for (int i = 0;i < items.size();i++) {
resultMap.put(items.get(i),rs.getString(items.get(i)));
}
result.add(resultMap);
}
return result;
} finally {
releaseConnection(conn, stmt, rs);
}
}
private static void releaseConnection(Connection conn, Statement stmt,
ResultSet rs) throws SQLException {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
}