getblob.html
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<TITLE>Getting BLOB Data from a Database Table
(Java Developers Almanac Example)
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<h3>
e256.
Getting BLOB Data from a Database Table</h3>
A BLOB is a reference to data in a database.
This example demonstrates how to retrieves bytes from a BLOB.
<pre>
try {
Statement stmt = <font color="#0066ff"><i>connection</i></font>.createStatement();
ResultSet rs = stmt.executeQuery(<font color="#0066ff"><i>"SELECT col_blob FROM mysql_all_table"</i></font>);
if (rs.next()) {
// Get the BLOB from the result set
Blob blob = rs.getBlob(<font color="#0066ff"><i>"col_blob"</i></font>);
// Get the number bytes in the BLOB
long blobLength = blob.length();
// Get bytes from the BLOB in a byte array
int pos = <font color="#0066ff"><i>1</i></font>; // position is 1-based
int len = <font color="#0066ff"><i>10</i></font>;
byte[] bytes = blob.getBytes(pos, len);
// Get bytes from the BLOB using a stream
InputStream is = blob.getBinaryStream();
int b = is.read();
}
} catch (IOException e) {
} catch (SQLException e) {
}
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Related Examples
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e251. <a class="eglink" href="CreateResultSet.html?l=rel">
Getting Rows from a Database Table
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e252. <a class="eglink" href="GetRsData.html?l=rel">
Getting Data from a Result Set
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e253. <a class="eglink" href="IsNull.html?l=rel">
Determining If a Fetched Value Is NULL
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e254. <a class="eglink" href="GetRsColCount.html?l=rel">
Getting the Column Names in a Result Set
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e255. <a class="eglink" href="GetRowCountUsingCount.html?l=rel">
Getting the Number of Rows in a Database Table
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e257. <a class="eglink" href="SelectLike.html?l=rel">
Matching with Wildcards in a SQL Statement
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Batching
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Deleting Data
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Drivers
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Importing and Exporting
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Inserting and Updating Data
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Oracle OBJECTs
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<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Oracle%20VARRAYs">
Oracle VARRAYs
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Procedures and Functions
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Scrollable Result Sets
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Tables
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Updatable Result Sets
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