specially marked sections. To build the program, the source code (<filename>*.pgc</filename>)

is first passed through the embedded SQL preprocessor, which converts it

to an ordinary C program (<filename>*.c</filename>), and afterwards it can be processed by a C

compiler. (For details about the compiling and linking see <xref linkend="ecpg-process"/>).

compiler. (For details about the compiling and linking see <xref linkend="ecpg-process"/>.)

Converted ECPG applications call functions in the libpq library

through the embedded SQL library (ecpglib), and communicate with

the PostgreSQL server using the normal frontend-backend protocol.

</programlisting>

These statements syntactically take the place of a C statement.

Depending on the particular statement, they can appear at the

global level or within a function. Embedded

global level or within a function.

</para>

<para>

Embedded

<acronym>SQL</acronym> statements follow the case-sensitivity rules of

normal <acronym>SQL</acronym> code, and not those of C. Also they allow nested

C-style commentsthat are part of the SQL standard. The C part of the

C-style commentsas per the SQL standard. The C part of the

program, however, follows the C standard of not accepting nested comments.

Embedded <acronym>SQL</acronym> statements likewise use SQL rules, not

C rules, for parsing quoted strings and identifiers.

(See <xref linkend="sql-syntax-strings"/> and

<xref linkend="sql-syntax-identifiers"/> respectively. Note that

ECPG assumes that <varname>standard_conforming_strings</varname>

is <literal>on</literal>.)

Of course, the C part of the program follows C quoting rules.

</para>

<para>

}

}

<xq,xe,xn,xus>{xqdouble}{addlitchar('\''); }

<xqc>{xqcquote}{

addlitchar('\\');

addlitchar('\'');

}

<xq,xe,xn,xus>{xqdouble}{addlit(yytext, yyleng); }

<xqc>{xqcquote}{addlit(yytext, yyleng); }

<xq,xqc,xn,xus>{xqinside}{addlit(yytext, yyleng); }

<xe>{xeinside} {

addlit(yytext, yyleng);

return UIDENT;

}

<xd,xui>{xddouble}{

addlitchar('"');

addlit(yytext, yyleng);

}

<xd,xui>{xdinside}{

addlit(yytext, yyleng);

#line 13 "strings.pgc"

{ECPGdo(__LINE__,0,1,NULL,0,ECPGst_normal,"select 'abcdef' , N'abcdef' as foo , E'abc\\bdef' as \"foo\" , U&'d\\0061t\\0061' as U&\"foo\" , U&'d!+000061t!+000061' UESCAPE '!' , $foo$abc$def$foo$",ECPGt_EOIT,

{ECPGdo(__LINE__,0,1,NULL,0,ECPGst_normal,"select 'abc''d\\ef' , N'abc''d\\ef' as foo , E'abc''d\\\\ef' as \"foo\"\"bar\" , U&'d\\0061t\\0061' as U&\"foo\"\"bar\" , U&'d!+000061t!+000061' UESCAPE '!' , $foo$abc$def$foo$",ECPGt_EOIT,

ECPGt_char,&(s1),(long)0,(long)1,(1)*sizeof(char),

ECPGt_NO_INDICATOR,NULL ,0L,0L,0L,

ECPGt_char,&(s2),(long)0,(long)1,(1)*sizeof(char),

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_process_output on line 13: OK: SET

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_execute on line 15: query: select 'abcdef' , N'abcdef' as foo , E'abc\bdef' as "foo" , U&'d\0061t\0061' as U&"foo" , U&'d!+000061t!+000061' UESCAPE '!' , $foo$abc$def$foo$; with 0 parameter(s) on connection ecpg1_regression

[NO_PID]: ecpg_execute on line 15: query: select 'abc''d\ef' , N'abc''d\ef' as foo , E'abc''d\\ef' as "foo""bar" , U&'d\0061t\0061' as U&"foo""bar" , U&'d!+000061t!+000061' UESCAPE '!' , $foo$abc$def$foo$; with 0 parameter(s) on connection ecpg1_regression

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_execute on line 15: using PQexec

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_process_output on line 15: correctly got 1 tuples with 6 fields

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_store_result on line 15: allocating memory for 1 tuples

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_get_data on line 15: RESULT:abcdef offset: -1; array: no

[NO_PID]: ecpg_get_data on line 15: RESULT:abc'd\ef offset: -1; array: no

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_store_result on line 15: allocating memory for 1 tuples

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_get_data on line 15: RESULT:abcdef offset: -1; array: no

[NO_PID]: ecpg_get_data on line 15: RESULT:abc'd\ef offset: -1; array: no

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_store_result on line 15: allocating memory for 1 tuples

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_get_data on line 15: RESULT: abcdef offset: -1; array: no

[NO_PID]: ecpg_get_data on line 15: RESULT: abc'd\ef offset: -1; array: no

[NO_PID]: sqlca: code: 0, state: 00000

[NO_PID]: ecpg_store_result on line 15: allocating memory for 1 tuples

[NO_PID]: sqlca: code: 0, state: 00000

abcdef abcdef abcdef data data abc$def

abc'd\ef abc'd\ef abc'd\ef data data abc$def

exec sql set standard_conforming_strings to on;

exec sql select 'abcdef',

N'abcdef' AS foo,

E'abc\bdef' AS "foo",

U&'d\0061t\0061' AS U&"foo",

exec sql select 'abc''d\ef',

N'abc''d\ef' AS foo,

E'abc''d\\ef' AS "foo""bar",

U&'d\0061t\0061' AS U&"foo""bar",

U&'d!+000061t!+000061' uescape '!',

$foo$abc$def$foo$

into :s1, :s2, :s3, :s4, :s5, :s6;

exec sql create table dyntest (name char (14), d float8, i int,

bignumber int8, b boolean, comment text,

day date);

exec sql insert into dyntest values ('first entry', 14.7, 14, 123045607890, true, 'The world''''s most advanced open source database.', '1987-07-14');

exec sql insert into dyntest values ('first entry', 14.7, 14, 123045607890, true, 'The world''s most advanced open source database.', '1987-07-14');

exec sql insert into dyntest values ('second entry', 1407.87, 1407, 987065403210, false, 'The elephant never forgets.', '1999-11-5');

exec sql prepare MYQUERY from :QUERY;