Welcome to the community. What you need to do is to query the column_balues of that item. For example: this one give me the data for that item stored in the column with columnId “date4”.
{
items(ids: 123456789) {
id
column_values(ids: "date4") {
value
text
}
}
}
If you don’t specify the columnId you get all values for all columns. For example this one gives all values and column names (title) for that item
{
items(ids: 123456789) {
id
column_values {
title
value
}
}
}