> Types are static within the context of a queryTypes in Python are also static within the context of a statement. That's not particularly meaningful, though, as programs don't run as individual statements in a vacuum. Just like SQL, the state that has been built up beforehand is quite significant to what each individual statement ends up meaning.
> types do not exist at compile time at all.
Same goes for SQL. Given the previous program, it is impossible to determine what the type of v is until you are ready to execute the SELECT statement. If the CREATE TABLE statement fails, v will not be the VARCHAR you think it is. If someone else modifies the world between your CREATE TABLE statement and your SELECT statement, v also will not be the VARCHAR you think it is. All you can do is throw the code at the database at runtime and hope it doesn't blow up.
> whereas in your example you are executing the statement.
What do you think "" + 42 executes to, then? The thing is, it doesn't execute because it doesn't satisfy the type constraints. It fails before execution. If it were a weakly typed language, like Javascript, then execution may be possible. Javascript produces "42".
> and is very comparable to the guarantees that a language like Typescript offers you.
Not at all. Something like Typescript provides guarantees during development. SQL, being a dynamically typed language, cannot know the types ahead of time – they don't exist until the program has already begun execution – and will throw errors at you in runtime after you've moved into production if you've encountered a problem.
Types in Python are also static within the context of a statement. That's not particularly meaningful, though, as programs don't run as individual statements in a vacuum. Just like SQL, the state that has been built up beforehand is quite significant to what each individual statement ends up meaning.
> types do not exist at compile time at all.
Same goes for SQL. Given the previous program, it is impossible to determine what the type of v is until you are ready to execute the SELECT statement. If the CREATE TABLE statement fails, v will not be the VARCHAR you think it is. If someone else modifies the world between your CREATE TABLE statement and your SELECT statement, v also will not be the VARCHAR you think it is. All you can do is throw the code at the database at runtime and hope it doesn't blow up.
> whereas in your example you are executing the statement.
What do you think "" + 42 executes to, then? The thing is, it doesn't execute because it doesn't satisfy the type constraints. It fails before execution. If it were a weakly typed language, like Javascript, then execution may be possible. Javascript produces "42".
> and is very comparable to the guarantees that a language like Typescript offers you.
Not at all. Something like Typescript provides guarantees during development. SQL, being a dynamically typed language, cannot know the types ahead of time – they don't exist until the program has already begun execution – and will throw errors at you in runtime after you've moved into production if you've encountered a problem.