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POC# check insert value is empty or null in cause of overwrite with empty string
 

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  1. POC# check insert value is empty or null in cause of overwrite with empty string
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    <p>I have a class with different attributes, lets say.</p> <pre><code>Object.attributeA Object.attributeB Object.attributeC Object.attributeD </code></pre> <p>However, they are not always filled. For example:</p> <pre><code>Object.attributeA = "string"; Object.attributeB = "string"; Object.attributeC = null; Object.attributeD = "string"; </code></pre> <p>My insert statement looks like this:</p> <pre><code>string sql = @"INSERT INTO TABLE ( attributeA, attributeB, attributeC, attributeAD ) values ( @attributeA, @attributeB, @attributeC, @attributeAD );"; SqlParameter[] parameters = { new SqlParameter("@attributeA", SqlDbType.NVarChar) {Value = attributeA}, new SqlParameter("@attributeB", SqlDbType.NVarChar) {Value = attributeB}, new SqlParameter("@attributeC", SqlDbType.NVarChar) {Value = attributeC}, new SqlParameter("@attributeD", SqlDbType.NVarChar) {Value = attributeD} }; ExecuteNoNQuery(sql, parameters); </code></pre> <p>How do I insert a null?</p> <p>(To confirm: when I update a row I want to keep the old value if the new value is null, with "" I just OVERWRITE the old value right?)</p> <p>Old row "abc" "abc" "abc" "abc"</p> <p>Update row: "string" "string" "abc" "string" </p> <p>AND NOT: "string" "string" "" "string"</p> <p>EDIT: I have two tables. I use the insert for the first table, add the attributes (sort of a temp save) AND THEN I take this table row for row update the 'real' table. The attributes in table 1 are always more then the real table. That's why after the insert of a "" I just overwrite the attribute in the real table.</p> <p>My update function looks something like this:</p> <pre><code>public void UpdateBatchToRealTable(Class, int id) { // Current Batch DataTable dt = DAL.Batch(id); // table 1 (temp table) -&gt; table 2 (real table) DataRow row = dt.Rows[0]; Object.attributeA = row["attributeA"].ToString(); Object.attributeB = row["attributeB"].ToString(); Object.attributeC = row["attributeC"].ToString(); Object.attributeD = row["attributeD"].ToString(); } </code></pre>
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    1. USDanny
    1. USDanny
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      1. POC# check insert value is empty or null in cause of overwrite with empty string
      1. This table or related slice is empty.
      1. VTUpMod
    1. COFor that you first have to get all the column values (previous) and then update as per your requirement. The best i think would be to make use of the SP where it will reject null updates rather than you retriving the value first and then doing the checking.
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      1. USZenwalker
    2. COJust to be sure I understand. When INSERT null is OK, when UPDATE null is not OK?
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      1. USSteve
    3. COYour statement is INSERT statement. In that case there won't be any old value!
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      1. USAnil Soman
 

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