wuchong commented on a change in pull request #10096: [FLINK-14623][table-api]
Add computed column information into TableSc…
URL: https://github.com/apache/flink/pull/10096#discussion_r343703577
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File path:
flink-table/flink-table-common/src/main/java/org/apache/flink/table/api/TableSchema.java
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@@ -373,8 +444,38 @@ public Builder() {
public Builder field(String name, DataType dataType) {
Preconditions.checkNotNull(name);
Preconditions.checkNotNull(dataType);
- fieldNames.add(name);
- fieldDataTypes.add(dataType);
+ columns.add(TableColumn.of(name, dataType));
+ return this;
+ }
+
+ /**
+ * Add a field with name, data type and computation expression.
+ * This column would be a computed column.
+ *
+ * <p>The call order of this method determines the order of
fields in the schema.
+ *
+ * @param name Field name
+ * @param dataType Field data type
+ * @param expression Computed column expression, it should be a
SQL-style expression whose
+ * identifiers should be all quoted and
expanded.
+ *
+ * It should be expanded because this
expression may be persisted
+ * then deserialized from the catalog, an
expanded identifier would
+ * avoid the ambiguity if there are same name
UDF referenced from
+ * different paths. For example, if there is
a UDF named "my_udf" from
+ * path "my_catalog.my_database", you could
pass in an expression like
+ * "my_catalog.my_database.my_udf(f0) + 1";
Review comment:
The identifiers should be quoted.
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