Fix signature of DBInterface.prepare

Author: lucianolorenti

src/tables.jl

@@ -69,13 +69,13 @@ end
 DBInterface.lastrowid(q::Query) = last_insert_rowid(q.stmt.db)
 
 """
-    DBInterface.prepare(db::SQLite.DB, sql::String)
+    DBInterface.prepare(db::SQLite.DB, sql::AbstractString)
 
 Prepare an SQL statement given as a string in the sqlite database; returns an `SQLite.Stmt` compiled object.
 See `DBInterface.execute`(@ref) for information on executing a prepared statement and passing parameters to bind.
 A `SQLite.Stmt` object can be closed (resources freed) using `DBInterface.close!`(@ref).
 """
-DBInterface.prepare(db::DB, sql::String) = Stmt(db, sql)
+DBInterface.prepare(db::DB, sql::AbstractString) = Stmt(db, sql)
 
 """
     DBInterface.execute(db::SQLite.DB, sql::String, [params])

test/runtests.jl

@@ -258,6 +258,12 @@ r = DBInterface.execute(db, "SELECT * FROM T") |> columntable
 @test r[1][2] == 2
 @test r[1][3] == 3
 
+
+r = DBInterface.execute(db, strip("   SELECT * FROM T  ")) |> columntable
+@test r[1][1] == 1
+@test r[1][2] == 2
+@test r[1][3] == 3
+
 @test SQLite.esc_id(["1", "2", "3"]) == "\"1\",\"2\",\"3\""
 
 SQLite.createindex!(db, "T", "x", "x_index"; unique=false)
@@ -292,4 +298,4 @@ r2 = DBInterface.execute(db, "SELECT * FROM T2") |> columntable
 # throw informative error on duplicate column names #193
 @test_throws ErrorException SQLite.load!((a=[1,2,3], A=[1,2,3]), db)
 
-end # @testset
+end # @testset