psql \copy command using scala process builder syntax error - scala

Question

I need to insert 1M rows of data to a table in postgres so i'm using postgres' copy from csv command. since the COPY needs a superuser account to work, i'm using the /copy instead.
here's my scala code:
val execCommand = Seq("psql", s"postgresql://$user:$pwd#$host:5432/$db", "-c", s"""\"\\copy $fullTableName (${columnsList}) from '${file.getAbsolutePath}' with delimiter ',' csv HEADER;\" """)
val result = execCommand.!!
println(result)
the command would look like this and works when run from my terminal:
psql postgresql://user:password#host:5432/db -c "\copy tableName (column1, column2, column3) from 'file_to_load.csv' with delimiter ',' csv HEADER;"
but when my code is run, it throws this error:
syntax error at or near ""\copy tableName (column1, column2, column3) with delimiter ',' csv HEADER;""
if i replace the command with a select query, it works fine. can someone help me identify the error on the \copy command? the syntax looks correct to me. maybe i'm missing out on something. i'm new to scala's process builder also so i also don't know if i need to fix the command. and if i do, how should i change this? thanks.

Answer 1

There is probably no need to run a psql command. You're usually better off using the corresponding JDBC API:
https://jdbc.postgresql.org/documentation/publicapi/org/postgresql/copy/CopyManager.html

Answer 2

posting how i fixed it using CopyManager. for documentation on this, see Matthias Berndt's comment.
object PgDbHandler {
def getConnection(db: ConnectionName, userName: String = user, pwd: String = password): Connection = {
Class.forName("org.postgresql.Driver")
DriverManager.getConnection(s"jdbc:postgresql://${db.sqlDns}/${db.databaseName}?user=$userName&password=$pwd&sslmode=require")
}
def copyFileToPg(file: File, fullTableName: String, columnsList: List[String]): Long = {
logger.info(s"Writing $file to postgres")
val conn = getConnection(db, user, pwd)
try{
val rowsInserted = new CopyManager(conn.asInstanceOf[BaseConnection])
.copyIn(s"COPY $fullTableName (${columnsList.mkString(",")}) FROM STDIN (DELIMITER ',',FORMAT csv, header true)",
new FileInputStream(file.getAbsolutePath))
logger.info(s"$rowsInserted row(s) inserted for file $file")
rowsInserted
}
finally
conn.close
}
}