Spark Delta Table Add new columns in middle Schema Evolution - azure

Question

Have to ingest a file with new column into a existing table structure.
create table sch.test (
name string ,
address string
) USING DELTA
--OPTIONS ('mergeSchema' 'true')
PARTITIONED BY (name)
LOCATION '/mnt/loc/fold'
TBLPROPERTIES (delta.autoOptimize.optimizeWrite = true, delta.autoOptimize.autoCompact = true);
Code to read the file:
val df = spark.read
.format("com.databricks.spark.csv")
.option("header", "true")
.load("/mnt/loc/fold")
display(df)
File in path contains below data
name,address
raghu,india
raj,usa
On writing it to a table,
import org.apache.spark.sql.functions._
df.withColumn("az_insert_ts", current_timestamp())
.withColumn("exec_run_id",lit("233"))
.withColumn("az_inp_file_name",lit("24234filename"))
.coalesce(12)
.write
.mode("append")
.option("mergeSchema", "true")
.format("delta")
.saveAsTable("sch.test")
display(spark.read.table("sch.test"))
Adding a new column,
name,address,age
raghu,india,12
raj,usa,13
Read the file,
val df = spark.read
.format("com.databricks.spark.csv")
.option("header", "true")
.load("/mnt/loc/fold")
display(df)
While writing into the table using insertInto,
import org.apache.spark.sql.functions._
df.withColumn("az_insert_ts", current_timestamp())
.withColumn("exec_run_id",lit("233"))
.withColumn("az_inp_file_name",lit("24234filename"))
.coalesce(12)
.write
.mode("append")
.option("mergeSchema", "true")
.format("delta")
.insertInto("sch.test")
display(spark.read.table("sch.test"))
Getting the below error,

Answer 1

Setting overwriteSchema to true will wipe out the old schema and let you create a completely new table.
import org.apache.spark.sql.functions._
df.withColumn(""az_insert_ts"", current_timestamp())
.withColumn(""exec_run_id"",lit(""233""))
.withColumn(""az_inp_file_name"",lit(""24234filename""))
.coalesce(12)
.write
.mode(""append"")
.option(""overwriteSchema"", ""true"")
.format(""delta"")
.insertInto(""sch.test"")
display(spark.read.table(""sch.test""))