Advanced Map Operations

Maps and arrays become most useful when you can convert them to display-friendly formats and build them from query results. ARRAY_JOIN: String Concat The tags array is converted to a comma-separated string. This is particularly useful for reports or CSV exports where array types are not supported. MAP_FROM_ENTRIES Each ROW represents a key-value pair. The resulting map can be queried using bracket notation like any other map. Combining Operations Real-world queries often chain multiple array and map operations: When chaining array functions, read from inside out. The innermost function executes first, and each outer function operates on the result of the previous one.