def __init__(self, name, raw_columns):
self.name = name
# Canonicalize the whitespace and then put back a little bit
# of pretty-printing, so that '.schema' is readable.
cnamelen = 0
columns1 = []
constraints = []
for c in raw_columns:
c = sql_lexer.canonicalize(c)
if sql_lexer.is_constraint(c):
n = c.find("(")
c = " " + c[:n] + " " + c[n:]
constraints.append(c)
else:
n = c.find(" ")
cnamelen = max(cnamelen, n)
columns1.append(c)
if not columns1:
raise ValueError("table "+name+" has no columns")
columns = []
for c in columns1:
n = c.find(" ")
columns.append(" {1:<{0}}{2}".format(cnamelen, c[:n], c[n:]))
self.schema = "CREATE TABLE "+name+" (\n"
self.schema += ",\n".join(columns)
if constraints:
self.schema += ",\n"
self.schema += ",\n".join(constraints)
self.schema += "\n)"
def ensure(self, db):
"""Ensure that an index with this specification exists in
database DB."""
existing = db.execute("SELECT type, sql FROM sqlite_master "
"WHERE name = ?", (self.name,)).fetchall()
if not existing:
db.executescript(self.schema)
return
if len(existing) > 1:
raise RuntimeError("more than one item named '{}'?!"
.format(self.name))
if existing[0] != "index":
raise RuntimeError("existing item named '{}' is not an index"
.format(self.name))
canon_schema = sql_lexer.canonicalize(self.schema)
existing_schema = sql_lexer.canonicalize(existing[1])
if canon_schema != existing_schema:
raise RuntimeError("schema mismatch for {}:\n"
"want: {}\n"
"got: {}"
.format(canon_schema, existing_schema))
