Add basic support for cast in expressions #957
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rust/src/io/exec/planner.rs
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| Ok(ArrowDataType::Timestamp(time_unit, None)) | ||
| } | ||
| _ => Err(Error::IO { | ||
| message: format!("Unsupported data type: {:?}. Supports: float, double, boolean, int, integer, date, datetime", data_type), |
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Also supports binary / string / booleans, right? I mean just in the error message.
| @@ -186,6 +250,13 @@ impl Planner { | |||
| SQLExpr::BinaryOp { left, op, right } => self.binary_expr(left, op, right), | |||
| SQLExpr::UnaryOp { op, expr } => self.unary_expr(op, expr), | |||
| SQLExpr::Value(value) => self.value(value), | |||
| // For example, DATE '2020-01-01' | |||
| SQLExpr::TypedString { data_type, value } => { | |||
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Does it mean we can actually do INT '1231' to cast an integer? Is there any restriction on the data_type supported?
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Could you add a few tests in rust?
Also , should we maintain a doc to describe what expression we support? Can be a follow up issue tho.
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Yeah other types work. I think the other one that is good to have is decimal.
I'll add some docs and tests in Rust.
| - Time unit | ||
| * - ``timestamp(0)`` | ||
| - Seconds | ||
| * - ``timestamp(3)`` |
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is the precision a limitation by the parser? Feel that timestamp(s), timestamp(ms) are easier to use. Curious how much effort to make it happen?
https://arrow.apache.org/docs/python/generated/pyarrow.timestamp.html
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Yeah that's unfortunately something that's not built in; it only allows integers.
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Ok, if this cannot be done in a few hours, let's just 🚢 it for now.
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The rest LGTM |
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Fixed #956. Allows casting, but also "typed literals" where you just put the type you want in front of the string.