//删除列
public static bool DeleteColumn(string dbname, string tableName, string colName, out string msg)
{
Database db = DbFunction.GetDB(dbname);
string sql = string.Format("alter table {0} drop column {1} ", tableName, colName);
msg = string.Empty;
//检查是否存在列信息
if (!CheckColumnExist(dbname, tableName, colName))
{
msg = "列" + colName + "不存在";
return(false);
}
try
{
DbFunction.ExecuteNonQuery(dbname, sql);
return(true);
}
catch (Exception ex)
{
msg = ex.Message;
}
return(false);
}
//创建表, 检查是否在数据库里存在这个表, 如果有的话, 判断是否有数据, 有数据则不允许删除
public static bool CreateTable(string dbname, string tableName, string Columns, string Key, out string msg)
{
msg = string.Empty;
//如果已经存在就返回
if (CheckTableExist(dbname, tableName))
{
msg = "表" + tableName + "已经存在";
return(false);
}
var sql = string.Empty;
if (Key.Length > 0)
{
sql = string.Format("create table {0}({1} CONSTRAINT PK_{0} PRIMARY KEY({2}))", tableName, Columns, Key);
}
else
{
sql = string.Format("create table {0}({1})", tableName, Columns.Remove(Columns.Length - 1));
}
try
{
DbFunction.ExecuteNonQuery(dbname, sql);
return(true);
}
catch (Exception ex)
{
msg = ex.Message;
}
return(false);
}
//修改表中的字段
public static bool ModifyColumn(string dbname, string tableName, string colName, string colType, string colLenght, string defaultValue, string nullable, out string msg)
{
Database db = DbFunction.GetDB(dbname);
msg = string.Empty;
//检查是否存在列信息
if (!CheckColumnExist(dbname, tableName, colName))
{
msg = "列" + colName + "不存在";
return(false);
}
var isOraDb = db.DBType == DataBaseType.ORA;
string sql = string.Format("alter table {0} alter column {1} ", tableName, colName);
if (isOraDb)
{
sql = string.Format("alter table {0} modify ( {1} ", tableName, colName);
}
sql += getColTypeStr(db, colType, colLenght);
//默认值
if (!string.IsNullOrEmpty(defaultValue))
{
sql += string.Format(" default {0}", defaultValue);
}
//是否为空
if (nullable == "0")
{
sql += " not null";
}
else
{
sql += " null";
}
if (isOraDb)
{
sql += ")";
}
try
{
DbFunction.ExecuteNonQuery(dbname, sql);
return(true);
}
catch (Exception ex)
{
msg = ex.Message;
}
return(false);
}