In my model I have a string txtSearche
with the value coming from a textbox like :
"hello all friends"
How can I write my statement dynamic adding WHERE text LIKE '%Text%'
for each word additional? something like 3 times:
WHERE Text LIKE '%@Text%'";
This is my code:
string[] wordsFromTxtSearche = txtSearche.Split(' ');
SqlCommand cmd = new SqlCommand();
cmd.Connection = connection;
cmd.CommandType = System.Data.CommandType.Text;
cmd.CommandText = @"SELECT * "
+ " FROM Forum开发者_如何学编程Thread "
+ " WHERE Text LIKE '%@Text%'";
cmd.Parameters.Add(new SqlParameter("@Text", txtSearche));
I suppose I need to do it with help of For loop but i don't know how. please help me
SQL won't interpolate parameters in strings, and you can use linq to clean up some messy looping code.
string[] words = txtSearche.Split(' ', StringSplitOption.RemoveEmptyEntries);
string[] paramNames = Enumerable.Range(1, words.Length)
.Select(i => "p" + i)
.ToArray();
string likeClause = string.Join("AND ",
paramNames.Select(name => "col like '%' + " + name + " + '%'");
SqlParmeter[] sqlParams = Enumerable.Range(1, words.Length)
.Select(i => new SqlParameter(paramNames[i], words[i]))
.ToArray();
SqlCommand cmd = new SqlCommand();
cmd.Connection = connection;
cmd.CommandType = System.Data.CommandType.Text;
cmd.CommandText = @"SELECT * FROM ForumThread WHERE " + likeClause;
cmd.Parameters.AddRange(sqlParams);
For what its worth, don't use like
to implement a forum search, use full text search instead.
See if this works... totally untested :)
SqlCommand cmd = new SqlCommand();
cmd.Connection = connection;
cmd.CommandType = System.Data.CommandType.Text;
string sql = "SELECT * FROM ForumThread WHERE ";
// assuming you have at least 1 item always in wordsFromTxtSearche
int count = 1;
foreach (string word in wordsFromTxtSearche)
{
if (count > 1) sql += " AND ";
sql += "Text LIKE @Text" + count.ToString();
cmd.Parameters.Add(new SqlParameter("@Text" + count.ToString(),
string.Format("%{0}%", word)));
count++;
}
cmd.CommandText = sql;
Something like:
string command = @"SELECT * FROM ForumThread where ";
bool first = false;
foreach (string word in words)
{
if (first)
command += " and ";
else
first = true;
command += " Text like '%" + word + "%' ";
}
cmd.CommandText = command;
If you wanted to stick to parameters, you have to create a scheme to generating a unique param, maybe something like:
string command = @"SELECT * FROM ForumThread where ";
bool first = false;
for(int i = 0, len = words.Length; i < len; i++)
{
string word = words[i];
if (first)
command += " and ";
else
first = true;
command += " Text like @param" + i.ToString() + " ";
cmd.Parameters.Add("@param" + i.ToString(), "%" + words[i] + "%");
}
cmd.CommandText = command;
HTH.
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