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Diffstat (limited to 'mycli/packages/completion_engine.py')
| -rw-r--r-- | mycli/packages/completion_engine.py | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/mycli/packages/completion_engine.py b/mycli/packages/completion_engine.py new file mode 100644 index 0000000..2b19c32 --- /dev/null +++ b/mycli/packages/completion_engine.py @@ -0,0 +1,295 @@ +import os +import sys +import sqlparse +from sqlparse.sql import Comparison, Identifier, Where +from sqlparse.compat import text_type +from .parseutils import last_word, extract_tables, find_prev_keyword +from .special import parse_special_command + + +def suggest_type(full_text, text_before_cursor): + """Takes the full_text that is typed so far and also the text before the + cursor to suggest completion type and scope. + + Returns a tuple with a type of entity ('table', 'column' etc) and a scope. + A scope for a column category will be a list of tables. + """ + + word_before_cursor = last_word(text_before_cursor, + include='many_punctuations') + + identifier = None + + # here should be removed once sqlparse has been fixed + try: + # If we've partially typed a word then word_before_cursor won't be an empty + # string. In that case we want to remove the partially typed string before + # sending it to the sqlparser. Otherwise the last token will always be the + # partially typed string which renders the smart completion useless because + # it will always return the list of keywords as completion. + if word_before_cursor: + if word_before_cursor.endswith( + '(') or word_before_cursor.startswith('\\'): + parsed = sqlparse.parse(text_before_cursor) + else: + parsed = sqlparse.parse( + text_before_cursor[:-len(word_before_cursor)]) + + # word_before_cursor may include a schema qualification, like + # "schema_name.partial_name" or "schema_name.", so parse it + # separately + p = sqlparse.parse(word_before_cursor)[0] + + if p.tokens and isinstance(p.tokens[0], Identifier): + identifier = p.tokens[0] + else: + parsed = sqlparse.parse(text_before_cursor) + except (TypeError, AttributeError): + return [{'type': 'keyword'}] + + if len(parsed) > 1: + # Multiple statements being edited -- isolate the current one by + # cumulatively summing statement lengths to find the one that bounds the + # current position + current_pos = len(text_before_cursor) + stmt_start, stmt_end = 0, 0 + + for statement in parsed: + stmt_len = len(text_type(statement)) + stmt_start, stmt_end = stmt_end, stmt_end + stmt_len + + if stmt_end >= current_pos: + text_before_cursor = full_text[stmt_start:current_pos] + full_text = full_text[stmt_start:] + break + + elif parsed: + # A single statement + statement = parsed[0] + else: + # The empty string + statement = None + + # Check for special commands and handle those separately + if statement: + # Be careful here because trivial whitespace is parsed as a statement, + # but the statement won't have a first token + tok1 = statement.token_first() + if tok1 and (tok1.value == 'source' or tok1.value.startswith('\\')): + return suggest_special(text_before_cursor) + + last_token = statement and statement.token_prev(len(statement.tokens))[1] or '' + + return suggest_based_on_last_token(last_token, text_before_cursor, + full_text, identifier) + + +def suggest_special(text): + text = text.lstrip() + cmd, _, arg = parse_special_command(text) + + if cmd == text: + # Trying to complete the special command itself + return [{'type': 'special'}] + + if cmd in ('\\u', '\\r'): + return [{'type': 'database'}] + + if cmd in ('\\T'): + return [{'type': 'table_format'}] + + if cmd in ['\\f', '\\fs', '\\fd']: + return [{'type': 'favoritequery'}] + + if cmd in ['\\dt', '\\dt+']: + return [ + {'type': 'table', 'schema': []}, + {'type': 'view', 'schema': []}, + {'type': 'schema'}, + ] + elif cmd in ['\\.', 'source']: + return[{'type': 'file_name'}] + + return [{'type': 'keyword'}, {'type': 'special'}] + + +def suggest_based_on_last_token(token, text_before_cursor, full_text, identifier): + if isinstance(token, str): + token_v = token.lower() + elif isinstance(token, Comparison): + # If 'token' is a Comparison type such as + # 'select * FROM abc a JOIN def d ON a.id = d.'. Then calling + # token.value on the comparison type will only return the lhs of the + # comparison. In this case a.id. So we need to do token.tokens to get + # both sides of the comparison and pick the last token out of that + # list. + token_v = token.tokens[-1].value.lower() + elif isinstance(token, Where): + # sqlparse groups all tokens from the where clause into a single token + # list. This means that token.value may be something like + # 'where foo > 5 and '. We need to look "inside" token.tokens to handle + # suggestions in complicated where clauses correctly + prev_keyword, text_before_cursor = find_prev_keyword(text_before_cursor) + return suggest_based_on_last_token(prev_keyword, text_before_cursor, + full_text, identifier) + else: + token_v = token.value.lower() + + is_operand = lambda x: x and any([x.endswith(op) for op in ['+', '-', '*', '/']]) + + if not token: + return [{'type': 'keyword'}, {'type': 'special'}] + elif token_v.endswith('('): + p = sqlparse.parse(text_before_cursor)[0] + + if p.tokens and isinstance(p.tokens[-1], Where): + # Four possibilities: + # 1 - Parenthesized clause like "WHERE foo AND (" + # Suggest columns/functions + # 2 - Function call like "WHERE foo(" + # Suggest columns/functions + # 3 - Subquery expression like "WHERE EXISTS (" + # Suggest keywords, in order to do a subquery + # 4 - Subquery OR array comparison like "WHERE foo = ANY(" + # Suggest columns/functions AND keywords. (If we wanted to be + # really fancy, we could suggest only array-typed columns) + + column_suggestions = suggest_based_on_last_token('where', + text_before_cursor, full_text, identifier) + + # Check for a subquery expression (cases 3 & 4) + where = p.tokens[-1] + idx, prev_tok = where.token_prev(len(where.tokens) - 1) + + if isinstance(prev_tok, Comparison): + # e.g. "SELECT foo FROM bar WHERE foo = ANY(" + prev_tok = prev_tok.tokens[-1] + + prev_tok = prev_tok.value.lower() + if prev_tok == 'exists': + return [{'type': 'keyword'}] + else: + return column_suggestions + + # Get the token before the parens + idx, prev_tok = p.token_prev(len(p.tokens) - 1) + if prev_tok and prev_tok.value and prev_tok.value.lower() == 'using': + # tbl1 INNER JOIN tbl2 USING (col1, col2) + tables = extract_tables(full_text) + + # suggest columns that are present in more than one table + return [{'type': 'column', 'tables': tables, 'drop_unique': True}] + elif p.token_first().value.lower() == 'select': + # If the lparen is preceeded by a space chances are we're about to + # do a sub-select. + if last_word(text_before_cursor, + 'all_punctuations').startswith('('): + return [{'type': 'keyword'}] + elif p.token_first().value.lower() == 'show': + return [{'type': 'show'}] + + # We're probably in a function argument list + return [{'type': 'column', 'tables': extract_tables(full_text)}] + elif token_v in ('set', 'order by', 'distinct'): + return [{'type': 'column', 'tables': extract_tables(full_text)}] + elif token_v == 'as': + # Don't suggest anything for an alias + return [] + elif token_v in ('show'): + return [{'type': 'show'}] + elif token_v in ('to',): + p = sqlparse.parse(text_before_cursor)[0] + if p.token_first().value.lower() == 'change': + return [{'type': 'change'}] + else: + return [{'type': 'user'}] + elif token_v in ('user', 'for'): + return [{'type': 'user'}] + elif token_v in ('select', 'where', 'having'): + # Check for a table alias or schema qualification + parent = (identifier and identifier.get_parent_name()) or [] + + tables = extract_tables(full_text) + if parent: + tables = [t for t in tables if identifies(parent, *t)] + return [{'type': 'column', 'tables': tables}, + {'type': 'table', 'schema': parent}, + {'type': 'view', 'schema': parent}, + {'type': 'function', 'schema': parent}] + else: + aliases = [alias or table for (schema, table, alias) in tables] + return [{'type': 'column', 'tables': tables}, + {'type': 'function', 'schema': []}, + {'type': 'alias', 'aliases': aliases}, + {'type': 'keyword'}] + elif (token_v.endswith('join') and token.is_keyword) or (token_v in + ('copy', 'from', 'update', 'into', 'describe', 'truncate', + 'desc', 'explain')): + schema = (identifier and identifier.get_parent_name()) or [] + + # Suggest tables from either the currently-selected schema or the + # public schema if no schema has been specified + suggest = [{'type': 'table', 'schema': schema}] + + if not schema: + # Suggest schemas + suggest.insert(0, {'type': 'schema'}) + + # Only tables can be TRUNCATED, otherwise suggest views + if token_v != 'truncate': + suggest.append({'type': 'view', 'schema': schema}) + + return suggest + + elif token_v in ('table', 'view', 'function'): + # E.g. 'DROP FUNCTION <funcname>', 'ALTER TABLE <tablname>' + rel_type = token_v + schema = (identifier and identifier.get_parent_name()) or [] + if schema: + return [{'type': rel_type, 'schema': schema}] + else: + return [{'type': 'schema'}, {'type': rel_type, 'schema': []}] + elif token_v == 'on': + tables = extract_tables(full_text) # [(schema, table, alias), ...] + parent = (identifier and identifier.get_parent_name()) or [] + if parent: + # "ON parent.<suggestion>" + # parent can be either a schema name or table alias + tables = [t for t in tables if identifies(parent, *t)] + return [{'type': 'column', 'tables': tables}, + {'type': 'table', 'schema': parent}, + {'type': 'view', 'schema': parent}, + {'type': 'function', 'schema': parent}] + else: + # ON <suggestion> + # Use table alias if there is one, otherwise the table name + aliases = [alias or table for (schema, table, alias) in tables] + suggest = [{'type': 'alias', 'aliases': aliases}] + + # The lists of 'aliases' could be empty if we're trying to complete + # a GRANT query. eg: GRANT SELECT, INSERT ON <tab> + # In that case we just suggest all tables. + if not aliases: + suggest.append({'type': 'table', 'schema': parent}) + return suggest + + elif token_v in ('use', 'database', 'template', 'connect'): + # "\c <db", "use <db>", "DROP DATABASE <db>", + # "CREATE DATABASE <newdb> WITH TEMPLATE <db>" + return [{'type': 'database'}] + elif token_v == 'tableformat': + return [{'type': 'table_format'}] + elif token_v.endswith(',') or is_operand(token_v) or token_v in ['=', 'and', 'or']: + prev_keyword, text_before_cursor = find_prev_keyword(text_before_cursor) + if prev_keyword: + return suggest_based_on_last_token( + prev_keyword, text_before_cursor, full_text, identifier) + else: + return [] + else: + return [{'type': 'keyword'}] + + +def identifies(id, schema, table, alias): + return id == alias or id == table or ( + schema and (id == schema + '.' + table)) |