Clean code

[datasette-connectors.git] / datasette_connectors / cursor.py

diff --git a/datasette_connectors/cursor.py b/datasette_connectors/cursor.py
new file mode 100644 (file)
index 0000000..6facf54
--- /dev/null
+++ b/datasette_connectors/cursor.py
@@ -0,0 +1,97 @@
+import re
+import sqlite3
+
+from .row import Row
+
+
+class OperationalError(Exception):
+    pass
+
+
+class Cursor:
+    class QueryNotSupported(Exception):
+        pass
+
+    def __init__(self, conn):
+        self.conn = conn
+        self.connector = conn.connector
+        self.rows = []
+        self.description = ()
+
+    def execute(
+        self,
+        sql,
+        params=None,
+        truncate=False,
+        custom_time_limit=None,
+        page_size=None,
+        log_sql_errors=True,
+    ):
+        if params is None:
+            params = {}
+        results = []
+        truncated = False
+        description = ()
+
+        # Normalize sql
+        sql = sql.strip()
+        sql = ' '.join(sql.split())
+
+        if sql == "select name from sqlite_master where type='table'" or \
+           sql == "select name from sqlite_master where type=\"table\"":
+            results = [{'name': name} for name in self.connector.table_names()]
+        elif sql == "select name from sqlite_master where rootpage = 0 and sql like '%VIRTUAL TABLE%USING FTS%'":
+            results = [{'name': name} for name in self.connector.hidden_table_names()]
+        elif sql == 'select 1 from sqlite_master where tbl_name = "geometry_columns"':
+            if self.connector.detect_spatialite():
+                results = [{'1': '1'}]
+        elif sql == "select name from sqlite_master where type='view'":
+            results = [{'name': name} for name in self.connector.view_names()]
+        elif sql.startswith("select count(*) from ["):
+            match = re.search(r'select count\(\*\) from \[(.*)\]', sql)
+            results = [{'count(*)': self.connector.table_count(match.group(1))}]
+        elif sql.startswith("select count(*) from "):
+            match = re.search(r'select count\(\*\) from (.*)', sql)
+            results = [{'count(*)': self.connector.table_count(match.group(1))}]
+        elif sql.startswith("PRAGMA table_info("):
+            match = re.search(r'PRAGMA table_info\((.*)\)', sql)
+            results = self.connector.table_info(match.group(1))
+        elif sql.startswith("select name from sqlite_master where rootpage = 0 and ( sql like \'%VIRTUAL TABLE%USING FTS%content="):
+            match = re.search(r'select name from sqlite_master where rootpage = 0 and \( sql like \'%VIRTUAL TABLE%USING FTS%content="(.*)"', sql)
+            if self.connector.detect_fts(match.group(1)):
+                results = [{'name': match.group(1)}]
+        elif sql.startswith("PRAGMA foreign_key_list(["):
+            match = re.search(r'PRAGMA foreign_key_list\(\[(.*)\]\)', sql)
+            results = self.connector.foreign_keys(match.group(1))
+        elif sql == "select 1 from sqlite_master where type='table' and name=?":
+            if self.connector.table_exists(params[0]):
+                results = [{'1': '1'}]
+        elif sql == "select sql from sqlite_master where name = :n and type=:t":
+            results = [{'sql': self.connector.table_definition(params['t'], params['n'])}]
+        elif sql == "select sql from sqlite_master where tbl_name = :n and type='index' and sql is not null":
+            results = [{'sql': sql} for sql in self.connector.indices_definition(params['n'])]
+        else:
+            try:
+                results, truncated, description = \
+                    self.connector.execute(
+                        sql,
+                        params=params,
+                        truncate=truncate,
+                        custom_time_limit=custom_time_limit,
+                        page_size=page_size,
+                        log_sql_errors=log_sql_errors,
+                    )
+            except OperationalError as ex:
+                raise sqlite3.OperationalError(*ex.args)
+
+        self.rows = [Row(result) for result in results]
+        self.description = description
+
+    def fetchall(self):
+        return self.rows
+
+    def fetchmany(self, max):
+        return self.rows[:max]
+
+    def __getitem__(self, index):
+        return self.rows[index]