getrsdata.html
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<TITLE>Getting Data from a Result Set
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<h3>
e252.
Getting Data from a Result Set</h3>
A result set contains the results of a SQL query. The results are
kept in a set of <font color="#0066ff"><i>rows</i></font>, one of which is designated the current
row. A row must be made current before data can be retrieved from
it. The result set maintains a reference to the current row called the
<font color="#0066ff"><i>cursor</i></font>.
<P> The cursor is positioned before the first row when a result set
is created. When a result set's <code>next()</code> method is called, the cursor
moves to the first row of the result set and that row becomes the
current row.
<P> There are two ways to retrieve the data from the current row.
The first uses a column index starting from 1. The second uses a
column name. For example, with the query `\cv{SELECT col1, col2 FROM
table}', the value for <code>col2</code> can be retrieved using a column index
of 2 or with the column name <code>col2</code>. This example demonstrates both
methods.
<pre>
try {
// Create a result set containing all data from my_table
Statement stmt = <font color="#0066ff"><i>connection</i></font>.createStatement();
ResultSet rs = stmt.executeQuery(<font color="#0066ff"><i>"SELECT * FROM my_table"</i></font>);
// Fetch each row from the result set
while (rs.next()) {
// Get the data from the row using the column index
String s = rs.getString(<font color="#0066ff"><i>1</i></font>);
// Get the data from the row using the column name
s = rs.getString(<font color="#0066ff"><i>"col_string"</i></font>);
}
} catch (SQLException e) {
}
</pre>
Here is another example of retrieving data from a result that
uses the various
<code>getXXX()</code> methods.
This example uses the table created in
<a href="../java.sql/CreateCompleteMySqlTable.html" class="eglink"><font size="-1"><b>e248</b> Creating a MySQL Table to Store Java Types</font></a>.
<pre>
try {
// Create a result set containing all data from mysql_all_table
Statement stmt = <font color="#0066ff"><i>connection</i></font>.createStatement();
ResultSet rs = stmt.executeQuery(<font color="#0066ff"><i>"SELECT * FROM mysql_all_table"</i></font>);
// Fetch each row from the result set
while (rs.next()) {
boolean bool = rs.getBoolean(<font color="#0066ff"><i>"col_boolean"</i></font>);
byte b = rs.getByte(<font color="#0066ff"><i>"col_byte"</i></font>);
short s = rs.getShort(<font color="#0066ff"><i>"col_short"</i></font>);
int i = rs.getInt(<font color="#0066ff"><i>"col_int"</i></font>);
long l = rs.getLong(<font color="#0066ff"><i>"col_long"</i></font>);
float f = rs.getFloat(<font color="#0066ff"><i>"col_float"</i></font>);
double d = rs.getDouble(<font color="#0066ff"><i>"col_double"</i></font>);
BigDecimal bd = rs.getBigDecimal(<font color="#0066ff"><i>"col_bigdecimal"</i></font>);
String str = rs.getString(<font color="#0066ff"><i>"col_string"</i></font>);
Date date = rs.getDate(<font color="#0066ff"><i>"col_date"</i></font>);
Time t = rs.getTime(<font color="#0066ff"><i>"col_time"</i></font>);
Timestamp ts = rs.getTimestamp(<font color="#0066ff"><i>"col_timestamp"</i></font>);
InputStream ais = rs.getAsciiStream(<font color="#0066ff"><i>"col_asciistream"</i></font>);
InputStream bis = rs.getBinaryStream(<font color="#0066ff"><i>"col_binarystream"</i></font>);
Blob blob = rs.getBlob(<font color="#0066ff"><i>"col_blob"</i></font>);
}
} catch (SQLException e) {
}
</pre>
<P><table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
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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
</a>
<br>
e253. <a class="eglink" href="IsNull.html?l=rel">
Determining If a Fetched Value Is NULL
</a>
<br>
e254. <a class="eglink" href="GetRsColCount.html?l=rel">
Getting the Column Names in a Result Set
</a>
<br>
e255. <a class="eglink" href="GetRowCountUsingCount.html?l=rel">
Getting the Number of Rows in a Database Table
</a>
<br>
e256. <a class="eglink" href="GetBlob.html?l=rel">
Getting BLOB Data from a Database Table
</a>
<br>
e257. <a class="eglink" href="SelectLike.html?l=rel">
Matching with Wildcards in a SQL Statement
</a>
<br>
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See also:
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Batching">
Batching
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Connections">
Connections
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<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Database%20Meta%20Data">
Database Meta Data
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Deleting%20Data">
Deleting Data
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Drivers">
Drivers
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Importing%20and%20Exporting">
Importing and Exporting
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Inserting%20and%20Updating%20Data">
Inserting and Updating Data
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Oracle%20OBJECTs">
Oracle OBJECTs
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Oracle%20VARRAYs">
Oracle VARRAYs
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Procedures%20and%20Functions">
Procedures and Functions
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Scrollable%20Result%20Sets">
Scrollable Result Sets
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Tables">
Tables
</a>
<a class="eglink" href="/egs/java.sql/pkg.html?l=rel#Updatable%20Result%20Sets">
Updatable Result Sets
</a>
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