{"id":2476,"date":"2014-07-09T08:52:08","date_gmt":"2014-07-09T00:52:08","guid":{"rendered":"http:\/\/kuki.idv.tw\/?p=2476"},"modified":"2014-07-09T08:52:08","modified_gmt":"2014-07-09T00:52:08","slug":"asp-net-c-3%e5%80%8b%e5%9f%b7%e8%a1%8csql%e7%9a%84%e6%96%b9%e6%b3%95%e8%aa%aa%e6%98%8e","status":"publish","type":"post","link":"https:\/\/www.kuki.idv.tw\/?p=2476","title":{"rendered":"ASP.NET C# 3\u500b\u57f7\u884cSQL\u7684\u65b9\u6cd5\u8aaa\u660e"},"content":{"rendered":"

ExecuteNonQuery()<\/strong><\/p>\n

\u7528\u6cd5\uff1aExecuteNonQuery\u7528\u4f86\u57f7\u884cINSERT\u3001UPDATE\u3001DELETE\u548c\u5176\u4ed6\u6c92\u6709\u8fd4\u56de\u503c\u5f97SQL\u547d\u4ee4\u3002\u4f8b\u5982\uff1aCREATE DATABASE \u548c CREATE TABLE \u547d\u4ee4\u3002<\/p>\n

\u7576\u4f7f\u7528 INSERT\u3001UPDATE\u3001DELETE\u6642\uff0cExecuteNonQuery\u8fd4\u56de\u88ab\u547d\u4ee4\u5f71\u97ff\u7684\u884c\u6578\u3002\u82e5\u662f\u7528\u5728\u5c0d\u5176\u4ed6\u547d\u4ee4\uff0c\u5247\u8fd4\u56de-1\u3002<\/p>\n

\n

ExecuteScalar()<\/strong><\/p>\n

\u7528\u6cd51\uff1aExecuteScalar \u57f7\u884c\u4e00\u500bSQL\u547d\u4ee4\u8fd4\u56de\u7d50\u679c\u96c6\u7684\u7b2c\u4e00\u5217\u7684\u7b2c\u4e00\u884c\u3002\u5b83\u7d93\u5e38\u7528\u4f86\u57f7\u884cSQL\u7684COUNT\u3001AVG\u3001MIN\u3001MAX \u548c SUM \u51fd\u6578\uff0c\u9019\u4e9b\u51fd\u6578\u90fd\u662f\u8fd4\u56de\u55ae\u884c\u55ae\u5217\u7684\u7d50\u679c\u96c6\u3002<\/p>\n

‘\u6ce8\u610f\uff1a’ExecuteScalar \u4e00\u822c\u8fd4\u56de\u4e00\u500bObject\u985e\u578b\uff0c\u56e0\u6b64\u5fc5\u9808\u628a\u5b83\u8f49\u63db\u70ba\u5f37\u985e\u578b\u3002\u5982\u679c\u8f49\u63db\u4e0d\u6b63\u78ba\uff0c.NET\u6846\u67b6\u5c31\u6703\u5f15\u767c InvalidCastException\u7570\u5e38\u3002<\/p>\n

\u7528\u6cd52\uff1aExecuteScalar \u7684\u53e6\u4e00\u500b\u666e\u904d\u7684\u7528\u6cd5\u662f\u5f9e\u8cc7\u6599\u5eab\u4e2d\u6aa2\u7d22BLOB(\u4e8c\u9032\u4f4d\u5927\u7269\u4ef6)\u3002\u4e0b\u9762\u7684\u4f8b\u5b50\u5f9ePubs\u8cc7\u6599\u5eab\u7684Pub_Info\u8868\u7684Logo\u6b04\u4f4d\u4e2d\u6aa2\u7d22\u5716\u50cf\uff0c\u4e26\u628a\u4ed6\u5c01\u88dd\u5230\u4e00\u500b\u9ede\u9663\u5716\u4e2d\u3002<\/p>\n

MemoryStream stream = new MemoryStream();<\/p>\n

SqlConnection conn = new SqlConnection(“\u9023\u7dda\u5b57\u4e32”);<\/p>\n

try
\n{
\nconn.open();
\nSqlCommand cmd = new SqlCommand(“SELECT logo FROM pub_info WHERE pub_id=’0736′”, conn);
\nbyte[] blob = (byte[]) cmd.ExecuteScalar();
\nstream.Write(blob, 0, blob.Length);
\nBitmap bitmap = new Bitmap(stream);<\/p>\n

\/\/ TODO\uff1a\u4f7f\u7528\u9ede\u9663\u5716
\nbitmap.Dispose();
\n}
\ncatch(SqlException ex)
\n{
\nConsole.WriteLine(ex.Message);
\n}
\nfinally
\n{
\nstream.Close();
\nconn.Close();
\n}<\/p>\n

\u7528\u6cd53\uff1a\u60a8\u4e5f\u8a31\u5c0d\u5982\u4f55\u628aBLOB\u5beb\u5165\u8cc7\u6599\u5eab\u611f\u8208\u8da3\uff0c\u7b54\u6848\u662f\u5728\u5305\u88dd\u4e86INSERT\u547d\u4ee4(\u8a72\u547d\u4ee4\u4e2d\u5305\u542b\u4e86\u985e\u578b\u70babyte[]\u7684\u8f38\u5165\u53c3\u6578)\u7684\u547d\u4ee4\u7269\u4ef6\u4e0a\u8abf\u7528ExcuteNonQuery\u65b9\u6cd5\u3002\u4e0b\u9762\u4f8b\u5b50\u5728Pubs\u8cc7\u6599\u5eab\u7684Pub_Info\u8868\u4e2d\u63d2\u5165\u4e00\u689d\u8a18\u9304\uff0c\u8a18\u9304\u7684Logo\u6b04\u4f4d\u5305\u542b\u4e00\u500bBLOB\u3002\n<\/p>\n

— \u5b9a\u7fa9\u548c\u521d\u59cb\u5316blob\u8b8a\u6578
\nFileStream stream = new FileStream(“Logo.jpg”, FileMode.Open);
\nbyte[] blob = new byte[stream.Length];
\nstream.Read(blob, 0, (int) stream.Length);
\nstream.Close();
\nSqlConnection conn = new SqlConnection(“\u9023\u7dda\u5b57\u4e32”);<\/p>\n

try
\n{
\nconn.open();
\nSqlCommand cmd = new SqlCommand(“INSERT INTO pub_info(pub_id, logo) VALUES(‘9937’, @logo)”, conn);
\ncmd.Parameters.Add(“@logo”, blob);
\ncmd.ExecuteNonQuery();
\n}
\ncatch(SqlException ex)
\n{
\nConsole.WriteLine(ex.Message);
\n}
\nfinally
\n{
\nstream.Close();
\nconn.Close();
\n}\n<\/p>\n

ExecuteReader()<\/strong><\/p>\n

\u7528\u6cd5\uff1aExecuteReader \u65b9\u6cd5\u5b58\u5728\u7684\u76ee\u7684\u53ea\u6709\u4e00\u500b\uff1a\u76e1\u53ef\u80fd\u5feb\u5730\u5c0d\u8cc7\u6599\u5eab\u9032\u884c\u67e5\u8a62\u4e26\u5f97\u5230\u7d50\u679c\u3002ExecuteReader \u8fd4\u56de\u4e00\u500bDataReader\u7269\u4ef6\uff1a\u5982\u679c\u5728SqlCommand\u7269\u4ef6\u4e2d\u8abf\u7528\uff0c\u5247\u8fd4\u56deSqlDataReader\uff1b\u5982\u679c\u5728OleDbCommand\u7269\u4ef6\u4e2d\u8abf\u7528\uff0c\u8fd4\u56de\u7684\u662fOleDbDataReader\u3002\u53ef\u4ee5\u8abf\u7528DataReader\u7684\u65b9\u6cd5\u548c\u5c6c\u6027\u53cd\u8986\u904b\u7b97\u8655\u7406\u7d50\u679c\u96c6\u3002\u5b83\u662f\u4e00\u500b\u5feb\u901f\u679a\u8209\u8cc7\u6599\u5eab\u67e5\u8a62\u7d50\u679c\u7684\u6a5f\u5236\uff0c\u662f\u552f\u8b80\u3001\u53ea\u9032\u7684\u3002\u5c0dSqlDataReader.Read\u7684\u6bcf\u6b21\u8abf\u7528\u90fd\u6703\u5f9e\u7d50\u679c\u96c6\u4e2d\u8fd4\u56de\u4e00\u884c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

ExecuteNonQuery() \u7528\u6cd5\uff1aExecuteNonQuery\u7528\u4f86\u57f7\u884cINSERT\u3001UPDATE\u3001D … \u95b1\u8b80\u5168\u6587\u3008ASP.NET C# 3\u500b\u57f7\u884cSQL\u7684\u65b9\u6cd5\u8aaa\u660e\u3009<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=\/wp\/v2\/posts\/2476"}],"collection":[{"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2476"}],"version-history":[{"count":1,"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=\/wp\/v2\/posts\/2476\/revisions"}],"predecessor-version":[{"id":2477,"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=\/wp\/v2\/posts\/2476\/revisions\/2477"}],"wp:attachment":[{"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2476"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2476"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kuki.idv.tw\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2476"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}