PL/SQL Lexer is a toolkit for solving real-world language problems, in PL/SQL.
See the individual packages for details on each procedure.
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TOKENIZER - Converts statements into PL/SQL tokens, and tokens back into strings.
Create tokens for SQL and PL/SQL statements:
function tokenize(p_source clob) return token_table;
Create a CLOB from tokens:
function concatenate(p_tokens in token_table) return clob;
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STATEMENT_SPLITTER Split multiple statements into individual statements based on a terminator.
Split statements like SQL*Plus and drops the delimiter. Delimiters must be on a line with only whitespace. Delimiters may be counted even if it's inside a string or comment:
function split_by_sqlplus_delimiter( p_statements in clob, p_sqlplus_delimiter in varchar2 default '/' ) return clob_table;
[EXPERIMENTAL] Split statements terminated by semicolons but keeps the final semicolon. This is probably the most useful version:
function split_by_semicolon( p_tokens in token_table ) return token_table_table;
[EXPERIMENTAL] Split statements like SQL*Plus and then also split by semicolon:
function split_by_sqlplus_del_and_semi( p_statements in clob, p_sqlplus_delimiter in varchar2 default '/' ) return token_table_table;
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STATEMENT_CLASSIFIER - Classify a statement as DDL, PL/SQL, SELECT, ALTER, etc.
procedure classify( p_tokens in token_table, p_category out varchar2, p_statement_type out varchar2, p_command_name out varchar2, p_command_type out number, p_lex_sqlcode out number, p_lex_sqlerrm out varchar2, p_start_index in number default 1 );
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STATEMENT_FEEDBACK - Get a message similar to SQL*Plus feedback messages.
procedure get_feedback_message( p_tokens in token_table, p_rowcount in number, p_success_message out varchar2, p_compile_warning_message out varchar2 );
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STATEMENT_TERMINATOR - Remove unnecessary terminating semicolon and SQL*Plus delimiters. This prepares a statement to run as dynamic SQL.
function remove_semicolon( p_tokens in token_table ) return token_table; function remove_sqlplus_delimiter( p_tokens in token_table, p_sqlplus_delimiter in varchar2 default '/' ) return token_table; function remove_sqlplus_del_and_semi( p_tokens in token_table, p_sqlplus_delimiter in varchar2 default '/' ) return token_table;
Click the "Download ZIP" button, extract the files, CD to the directory with those files, connect to SQL*Plus, and run these commands:
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Create objects and packages on the desired schema:
alter session set current_schema=&schema_name; @install
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Install unit tests (optional):
alter session set current_schema=&schema_name; @install_unit_tests
alter session set current_schema=&schema_name;
@uninstall
PLSQL_LEXER provides functionality for handling groups of statements. This can be useful for a patch system, a logging utility, or a private SQL Fiddle.
The example below shows almost all of the steps to build the backend for a private SQL Fiddle: a website where users enter "a bunch of statements" in a window and Oracle must run and report on their success. The basic steps are:
- split the string into multiple statements and loop through them
- classify statement, for example to disallow anonymous PL/SQL blocks
- remove semicolons from some statements to prepare them for dynamic SQL
- Run each statement
- Report on the success or failure of each statement
After following the installation steps above this code should be runnable:
declare
--A collection of statements separated by semicolons.
--These may come from a website, text file, etc.
v_statements clob := q'<
create table my_table(a number);
insert into my_table values(1);
begin null; end;
udpate my_table set a = 2;
>';
v_split_statements token_table_table;
v_category varchar2(100);
v_statement_type varchar2(100);
v_command_name varchar2(64);
v_command_type number;
v_lex_sqlcode number;
v_lex_sqlerrm varchar2(4000);
begin
--Tokenize and split the string into multiple statements.
v_split_statements := statement_splitter.split_by_semicolon(
tokenizer.tokenize(v_statements));
--Loop through the statements.
for i in 1 .. v_split_statements.count loop
--Classify each statement.
statement_classifier.classify(
p_tokens => v_split_statements(i),
p_category => v_category,
p_statement_type => v_statement_type,
p_command_name => v_command_name,
p_command_type => v_command_type,
p_lex_sqlcode => v_lex_sqlcode,
p_lex_sqlerrm => v_lex_sqlerrm
);
--For debugging, print the statement and COMMAND_NAME.
dbms_output.put_line(chr(10)||'Statement '||i||' : '||
replace(replace(
tokenizer.concatenate(v_split_statements(i))
,chr(10)), chr(9)));
dbms_output.put_line('Command Name: '||v_command_name);
--Handle different command types.
--
--Prevent Anonymous Blocks from running.
if v_command_name = 'PL/SQL EXECUTE' then
dbms_output.put_line('Error : Anonymous PL/SQL blocks not allowed.');
--Warning message if "Invalid" - probably a typo.
elsif v_command_name = 'Invalid' then
dbms_output.put_line('Warning : Could not classify this statement, '||
'please check for a typo: '||
replace(replace(substr(
tokenizer.concatenate(v_split_statements(i))
, 1, 30), chr(10)), chr(9)));
--Warning message if "Nothing"
elsif v_command_name = 'Nothing' then
dbms_output.put_line('No statements found.');
--Run everything else.
else
declare
v_success_message varchar2(4000);
v_compile_warning_message varchar2(4000);
begin
--Remove extra semicolons and run.
execute immediate to_clob(tokenizer.concatenate(
statement_terminator.remove_semicolon(
p_tokens => v_split_statements(i))));
--Get the feedback message.
statement_feedback.get_feedback_message(
p_tokens => v_split_statements(i),
p_rowcount => sql%rowcount,
p_success_message => v_success_message,
p_compile_warning_message => v_compile_warning_message
);
--Print success message.
dbms_output.put_line('Status : '||v_success_message);
--Print compile warning message, if any.
--This happens when objects successfully compile but are invalid.
if v_compile_warning_message is not null then
dbms_output.put_line('Compile warning: '||v_compile_warning_message);
end if;
exception when others then
dbms_output.put_line('Error : '||dbms_utility.format_error_stack||
dbms_utility.format_error_backtrace);
end;
end if;
end loop;
end;
/
Results:
Statement 1 : create table my_table(a number);
Command Name: CREATE TABLE
Status : Table created.
Statement 2 : insert into my_table values(1);
Command Name: INSERT
Status : 1 row created.
Statement 3 : begin null; end;
Command Name: PL/SQL EXECUTE
Error : Anonymous PL/SQL blocks are not allowed.
Statement 4 : udpate my_table set a = 2;
Command Name: Invalid
Warning : Could not classify this statement, please check for a typo: udpate my_table set a = 2;
Version 1.0.0 may be ready after these steps:
- Finish statement_terminator unit tests.
- Add statement_feedback unit tests.
- Add statement (view) expander program?
- Fix/refactor statement splitter bug, more unit tests.
- Thoroughly test by using code in other project I'm trying to open source?
plsql_lexer
is licensed under the LGPL.