diff options
| -rw-r--r-- | doc/src/sgml/ref/psql-ref.sgml | 10 | ||||
| -rw-r--r-- | src/bin/psql/psqlscanslash.l | 18 | ||||
| -rw-r--r-- | src/fe_utils/psqlscan.l | 42 | ||||
| -rw-r--r-- | src/include/fe_utils/psqlscan_int.h | 2 | ||||
| -rw-r--r-- | src/test/regress/expected/psql.out | 26 | ||||
| -rw-r--r-- | src/test/regress/sql/psql.sql | 18 |
6 files changed, 115 insertions, 1 deletions
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index 60bafa81754..e7a3e17c67b 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -783,6 +783,10 @@ testdb=> The forms <literal>:'<replaceable>variable_name</>'</literal> and <literal>:"<replaceable>variable_name</>"</literal> described there work as well. + The <literal>:{?<replaceable>variable_name</>}</> syntax allows + testing whether a variable is defined. It is substituted by + TRUE or FALSE. + Escaping the colon with a backslash protects it from substitution. </para> <para> @@ -3939,6 +3943,12 @@ testdb=> <userinput>INSERT INTO my_table VALUES (:'content');</userinput> </para> <para> + The <literal>:{?<replaceable>name</>}</> special syntax returns TRUE + or FALSE depending on whether the variable exists or not, and is thus + always substituted, unless the colon is backslash-escaped. + </para> + + <para> The colon syntax for variables is standard <acronym>SQL</acronym> for embedded query languages, such as <application>ECPG</application>. The colon syntaxes for array slices and type casts are diff --git a/src/bin/psql/psqlscanslash.l b/src/bin/psql/psqlscanslash.l index db7a1b9eead..9a53cb3e02b 100644 --- a/src/bin/psql/psqlscanslash.l +++ b/src/bin/psql/psqlscanslash.l @@ -281,6 +281,10 @@ other . unquoted_option_chars = 0; } +:\{\?{variable_char}+\} { + psqlscan_test_variable(cur_state, yytext, yyleng); + } + :'{variable_char}* { /* Throw back everything but the colon */ yyless(1); @@ -295,6 +299,20 @@ other . ECHO; } +:\{\?{variable_char}* { + /* Throw back everything but the colon */ + yyless(1); + unquoted_option_chars++; + ECHO; + } + +:\{ { + /* Throw back everything but the colon */ + yyless(1); + unquoted_option_chars++; + ECHO; + } + {other} { unquoted_option_chars++; ECHO; diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l index 27689d72da8..4375142a007 100644 --- a/src/fe_utils/psqlscan.l +++ b/src/fe_utils/psqlscan.l @@ -745,9 +745,13 @@ other . PQUOTE_SQL_IDENT); } +:\{\?{variable_char}+\} { + psqlscan_test_variable(cur_state, yytext, yyleng); + } + /* * These rules just avoid the need for scanner backup if one of the - * two rules above fails to match completely. + * three rules above fails to match completely. */ :'{variable_char}* { @@ -762,6 +766,17 @@ other . ECHO; } +:\{\?{variable_char}* { + /* Throw back everything but the colon */ + yyless(1); + ECHO; + } +:\{ { + /* Throw back everything but the colon */ + yyless(1); + ECHO; + } + /* * Back to backend-compatible rules. */ @@ -1442,3 +1457,28 @@ psqlscan_escape_variable(PsqlScanState state, const char *txt, int len, psqlscan_emit(state, txt, len); } } + +void +psqlscan_test_variable(PsqlScanState state, const char *txt, int len) +{ + char *varname; + char *value; + + varname = psqlscan_extract_substring(state, txt + 3, len - 4); + if (state->callbacks->get_variable) + value = state->callbacks->get_variable(varname, PQUOTE_PLAIN, + state->cb_passthrough); + else + value = NULL; + free(varname); + + if (value != NULL) + { + psqlscan_emit(state, "TRUE", 4); + free(value); + } + else + { + psqlscan_emit(state, "FALSE", 5); + } +} diff --git a/src/include/fe_utils/psqlscan_int.h b/src/include/fe_utils/psqlscan_int.h index c70ff29f4ef..e9b351756b9 100644 --- a/src/include/fe_utils/psqlscan_int.h +++ b/src/include/fe_utils/psqlscan_int.h @@ -142,5 +142,7 @@ extern char *psqlscan_extract_substring(PsqlScanState state, extern void psqlscan_escape_variable(PsqlScanState state, const char *txt, int len, PsqlScanQuoteType quote); +extern void psqlscan_test_variable(PsqlScanState state, + const char *txt, int len); #endif /* PSQLSCAN_INT_H */ diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out index 836d8510fd2..3818cfea7e4 100644 --- a/src/test/regress/expected/psql.out +++ b/src/test/regress/expected/psql.out @@ -3014,6 +3014,32 @@ bar 'bar' "bar" \echo 'should print #8-1' should print #8-1 \endif +-- :{?...} defined variable test +\set i 1 +\if :{?i} + \echo '#9-1 ok, variable i is defined' +#9-1 ok, variable i is defined +\else + \echo 'should not print #9-2' +\endif +\if :{?no_such_variable} + \echo 'should not print #10-1' +\else + \echo '#10-2 ok, variable no_such_variable is not defined' +#10-2 ok, variable no_such_variable is not defined +\endif +SELECT :{?i} AS i_is_defined; + i_is_defined +-------------- + t +(1 row) + +SELECT NOT :{?no_such_var} AS no_such_var_is_not_defined; + no_such_var_is_not_defined +---------------------------- + t +(1 row) + -- SHOW_CONTEXT \set SHOW_CONTEXT never do $$ diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql index ddae1bf1e7e..b45da9bb8de 100644 --- a/src/test/regress/sql/psql.sql +++ b/src/test/regress/sql/psql.sql @@ -572,6 +572,24 @@ select \if false \\ (bogus \else \\ 42 \endif \\ forty_two; \echo 'should print #8-1' \endif +-- :{?...} defined variable test +\set i 1 +\if :{?i} + \echo '#9-1 ok, variable i is defined' +\else + \echo 'should not print #9-2' +\endif + +\if :{?no_such_variable} + \echo 'should not print #10-1' +\else + \echo '#10-2 ok, variable no_such_variable is not defined' +\endif + +SELECT :{?i} AS i_is_defined; + +SELECT NOT :{?no_such_var} AS no_such_var_is_not_defined; + -- SHOW_CONTEXT \set SHOW_CONTEXT never |