diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ecpg.sgml | 59 |
1 files changed, 54 insertions, 5 deletions
diff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml index 419574e9ea6..14dcbdb4e32 100644 --- a/doc/src/sgml/ecpg.sgml +++ b/doc/src/sgml/ecpg.sgml @@ -7066,7 +7066,7 @@ EXECUTE IMMEDIATE <replaceable class="parameter">string</replaceable> <term><replaceable class="parameter">string</replaceable></term> <listitem> <para> - A literal C string or a host variable containing the SQL + A literal string or a host variable containing the SQL statement to be executed. </para> </listitem> @@ -7075,6 +7075,30 @@ EXECUTE IMMEDIATE <replaceable class="parameter">string</replaceable> </refsect1> <refsect1> + <title>Notes</title> + + <para> + In typical usage, the <replaceable>string</replaceable> is a host + variable reference to a string containing a dynamically-constructed + SQL statement. The case of a literal string is not very useful; + you might as well just write the SQL statement directly, without + the extra typing of <command>EXECUTE IMMEDIATE</command>. + </para> + + <para> + If you do use a literal string, keep in mind that any double quotes + you might wish to include in the SQL statement must be written as + octal escapes (<literal>\042</literal>) not the usual C + idiom <literal>\"</literal>. This is because the string is inside + an <literal>EXEC SQL</literal> section, so the ECPG lexer parses it + according to SQL rules not C rules. Any embedded backslashes will + later be handled according to C rules; but <literal>\"</literal> + causes an immediate syntax error because it is seen as ending the + literal. + </para> + </refsect1> + + <refsect1> <title>Examples</title> <para> @@ -7388,7 +7412,7 @@ EXEC SQL OPEN :curname1; <refsynopsisdiv> <synopsis> -PREPARE <replaceable class="parameter">name</replaceable> FROM <replaceable class="parameter">string</replaceable> +PREPARE <replaceable class="parameter">prepared_name</replaceable> FROM <replaceable class="parameter">string</replaceable> </synopsis> </refsynopsisdiv> @@ -7421,9 +7445,10 @@ PREPARE <replaceable class="parameter">name</replaceable> FROM <replaceable clas <term><replaceable class="parameter">string</replaceable></term> <listitem> <para> - A literal C string or a host variable containing a preparable - statement, one of the SELECT, INSERT, UPDATE, or - DELETE. + A literal string or a host variable containing a preparable + SQL statement, one of SELECT, INSERT, UPDATE, or DELETE. + Use question marks (<literal>?</literal>) for parameter values + to be supplied at execution. </para> </listitem> </varlistentry> @@ -7431,6 +7456,30 @@ PREPARE <replaceable class="parameter">name</replaceable> FROM <replaceable clas </refsect1> <refsect1> + <title>Notes</title> + + <para> + In typical usage, the <replaceable>string</replaceable> is a host + variable reference to a string containing a dynamically-constructed + SQL statement. The case of a literal string is not very useful; + you might as well just write a direct SQL <command>PREPARE</command> + statement. + </para> + + <para> + If you do use a literal string, keep in mind that any double quotes + you might wish to include in the SQL statement must be written as + octal escapes (<literal>\042</literal>) not the usual C + idiom <literal>\"</literal>. This is because the string is inside + an <literal>EXEC SQL</literal> section, so the ECPG lexer parses it + according to SQL rules not C rules. Any embedded backslashes will + later be handled according to C rules; but <literal>\"</literal> + causes an immediate syntax error because it is seen as ending the + literal. + </para> + </refsect1> + + <refsect1> <title>Examples</title> <programlisting> char *stmt = "SELECT * FROM test1 WHERE a = ? AND b = ?"; |