使用 jq 从 JSON 中的嵌套数组中选择 jq 给出空结果

Question

I've been racking my brains over this because on its face, the jq statement I'm using should produce the desired result, but using a tool like jqplay to test gives me a blank result....

Here is the JSON I'm using:

{
  "DBInventory":
    {
      "InventoryID": "ABSCBD",
      "Inventory":[
            {
              "Sys1": 
                {
                  "folder":[
                    {
                      "Scripts":
                        {
                          "files": [
                            "FileName1O",
                            "FileName2O"
                            ]
                        }
                        
                    },
                    {
                      "Schemas":
                        {
                          "files": [
                            "FileName1S",
                            "FileName2S"
                            ]
                        }
                                   
                    },
                    {
                      "StoredProcedures":
                        {
                          "files": [
                            "FileName1SP",
                            "FileName2SP",
                            "FileName3SP"
                            ]
                        }
                            
                    },
                    {
                      "Tables":
                        {
                          "files": [
                            "FileName1T",
                            "FileName2T"
                            ]
                        }
                                      
                    }
                    ]
                }
                
           
            },
            {
              "Sys2": 
                {
                  "folder":[
                    {
                      "MaintScripts":
                        {
                          "files": [
                            "FileName1",
                            "FileName2"
                            ]
                        }
                        
                    },
                    {
                      "Schemas":
                        {
                          "files": [
                            "FileName1",
                            "FileName2"
                            ]
                        }
                                 
                    },
                    {
                      "StoredProcedures":
                        {
                          "files": [
                            "FileName1",
                            "FileName2"
                            ]
                        }
                              
                    },
                    {
                      "Tables":
                        {
                          "files": [
                            "FileName1",
                            "FileName2"
                            ]
                        }
                                        
                    },
                    {
                      "ExternalTables":
                        {
                          "files": [
                            "FileName1",
                            "FileName2"
                            ]
                        }
                              
                    }, 
                    {
                      "Scripts":
                        {
                          "files": [
                            "FileName1",
                            "FileName2"
                            ]
                        }
                                       
                    },
                    {
                      "Views":
                        {
                          "files": [
                            "FileName1v",
                            "FileName2v"
                            ]
                        }
                                       
                    }
                    ]
                }
            }
        ]
    }
  
}

I'm trying to select an object only return the filenames in the array under it like so (say I wanted just the files in 'Schemas' for 'Sys1'). The desired output would be:

["Filename1S","Filename2S"]

from this section:

Inventory > Sys1 > folder > Schemas

The jq statement I've been invoking is:

.DBInventory.Inventory[0][] | select(any(.folder[]; .Key == "Schemas")) | .files[]

Any help would be greatly appreciated. I think I'm close, but the whole blank output has thrown me for a loop.

Answer 1

You don't need a select() at all here. Consider:

jq '.DBInventory.Inventory[0][].folder[].Schemas?.files // empty'

Answer 2

The JSON data is not completely regular, so you could specify the path of interest more precisely, or sprinkle some "bailouts" (such as // empty or ? ) into the query, eg:

.DBInventory.Inventory[].Sys1 // empty
| (.folder[].Schemas // empty).files

or simply:

try (.DBInventory.Inventory[].Sys1.folder[].Schemas.files) // empty