@Override
public String buildUpdateSql(Object entity, Connection conn) throws SQLException {
AnnotationUtil annotationUtil = AnnotationUtil.getInstance();
// 获取表名
String tableName = annotationUtil.getAnnotationTableName(entity.getClass());
// 获取主键名
String[] primaryKeyNames = annotationUtil.getPrimaryKey(entity.getClass());
// 获取实体类存放的属性名和值
Map<String, Object> beanMap = annotationUtil.getBeanInfo(entity);
/**
* select * from tablename where 1=0的意义 此语句的作用是: 打开此记录集,但并不从记录集中读取任何记录
* 直观点说就是,为保护记录集数据,仅做打开,是只做插入记录时用到
*/
List<ColumnMeta> list = DaoOptemplate.getInstance().refresh(tableName, conn);
int columnCount = list.size();
StringBuffer valueBuffer = new StringBuffer("update " + tableName + " set ");
String whereCondition = "";
/** 此处用于判断实体的存在性 若存在则SQL语句组装完成，将where条件中的id补入 */
String word = " where ";
boolean flag = false;
for (int i = 0; i < columnCount; i++) {
ColumnMeta cm = list.get(i);
String columnName = cm.getColumnName();
String columnType = cm.getColumnType();
Object columnValue = beanMap.get(columnName);
if (columnValue == null) {
continue;
}
if (isPrimaryKey(columnName, primaryKeyNames)) {
whereCondition += word + getConditionSyntax(columnName, columnType, columnValue);
if (primaryKeyNames.length > 1) {
word = " and ";
}
} else {
if (columnValue != null) {
flag = true;
// 若为最后一个
if (i == columnCount) {
valueBuffer.append(getConditionSyntax(columnName, columnType, columnValue));
} else {
valueBuffer.append(getConditionSyntax(columnName, columnType, columnValue) + ",");
}
}
}
}
if (!flag) {
return null;
}
// 获取最后一个逗号到总长度的大小
int quoteApartLength = valueBuffer.length() - valueBuffer.toString().lastIndexOf(",");
if (quoteApartLength == 1) {
valueBuffer.deleteCharAt(valueBuffer.toString().lastIndexOf(","));
}
String sql = valueBuffer.toString() + whereCondition;
return sql;
}
@Override
public String buildDeleteSql(Object entity, Connection conn) throws SQLException, Exception {
AnnotationUtil annotationUtil = AnnotationUtil.getInstance();
// 获取表名
String tableName = annotationUtil.getAnnotationTableName(entity.getClass());
// 获取主键名
String[] primaryKeyNames = annotationUtil.getPrimaryKey(entity.getClass());
// 获取实体类存放的属性名和值
Map<String, Object> beanMap = annotationUtil.getBeanInfo(entity);
String sql = "delete from " + tableName;
String whereCondition = "";
boolean flag = false;
/** 此处用于判断实体的存在性 若存在则SQL语句组装完成，将where条件中的id补入 */
String word = " where ";
for (String columnName : primaryKeyNames) {
String columnType = entity.getClass().getDeclaredField(columnName).getType().getSimpleName();
Object columnValue = beanMap.get(columnName);
if (columnValue == null) {
flag = true;
continue;
}
whereCondition += word + getConditionSyntax(columnName, columnType, columnValue);
if (primaryKeyNames.length > 1) {
word = " and ";
}
}
// 如果主键的值为null，则通过普通条件查询
if (flag) {
List<ColumnMeta> list = DaoOptemplate.getInstance().refresh(tableName, conn);
int columnCount = list.size();
for (int i = 0; i < columnCount; i++) {
ColumnMeta cm = list.get(i);
String columnName = cm.getColumnName();
if (isPrimaryKey(columnName, primaryKeyNames)) {
continue;
}
String columnType = cm.getColumnType();
Object columnValue = beanMap.get(columnName);
if (columnValue == null) {
continue;
}
whereCondition += word + getConditionSyntax(columnName, columnType, columnValue);
if (whereCondition.contains("where")) {
word = " and ";
}
}
}
if (!whereCondition.contains("where")) {
throw new SQLException("查询的主键的值不能为空！");
}
sql += whereCondition;
return sql;
}
